RFC4008

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Network Working Group R. Rohit Request for Comments: 4008 Mascon Global Limited Category: Standards Track P. Srisuresh

                                                Caymas Systems, Inc.
                                                     R. Raghunarayan
                                                              N. Pai
                                                 Cisco Systems, Inc.
                                                             C. Wang
                                                       Bank One Corp
                                                          March 2005
 Definitions of Managed Objects for Network Address Translators (NAT)

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2005).

Abstract

This memo defines a portion of the Management Information Base (MIB) for devices implementing Network Address Translator (NAT) function. This MIB module may be used for configuration as well as monitoring of a device capable of NAT function.

   4.6.  RFC 3489 NAPT Variations, NAT Session and Bind Tables...  7

Introduction

This memo defines a portion of the Management Information Base (MIB) for devices implementing NAT function. This MIB module may be used for configuration and monitoring of a device capable of NAT function. NAT types and their characteristics are defined inRFC2663. Traditional NAT function, in particular is defined in RFC3022. This MIB does not address the firewall functions and must not be used for configuring or monitoring these. Section 2 provides references to the SNMP management framework, which was used as the basis for the MIB module definition. Section 3 describes the terms used throughout the document. Section 4 provides an overview of the key objects, their inter-relationship, and how the MIB module may be used to configure and monitor a NAT device. Lastly, section 5 has the complete NAT MIB definition.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC2119.

The Internet-Standard Management Framework

For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 RFC3410.

Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP).

Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 RFC2578, STD 58, RFC 2579 RFC2579 and STD 58, RFC 2580 RFC2580.

Terminology

Definitions for a majority of the terms used throughout the document may be found in RFC 2663 RFC2663. Additional terms that further classify NAPT implementations are defined in RFC 3489 RFC3489. Listed below are terms used in this document.

Address realm - An address realm is a realm of unique network addresses that are routable within the realm. For example, an enterprise address realm could be constituted of private IP addresses in the ranges specified in RFC 1918 RFC1918, which are routable within the enterprise, but not across the Internet. A public realm is constituted of globally unique network addresses.

Symmetric NAT - Symmetric NAT, as defined in RFC 3489 RFC3489, is a variation of Network Address Port Translator (NAPT). Symmetric NAT does not use port bind for translation across all sessions originating from the same private host. Instead, it assigns a new public port to each new session, irrespective of whether the new session used the same private end-point as before.

Bind or Binding - Several variations of the term 'Bind' (or 'Binding') are used throughout the document. Address Bind (or Address Binding) is a tuple of (Private IP address, Public IP Address) used for translating an IP address end-point in IP packets. Port Bind (or, Port Binding, or Address Port Bind, or Address Port Binding) is a tuple of (transport protocol, Private IP address, Private port, Public IP Address, Public port) used for translating a port end-point tuple of (transport protocol, IP address, port). Bind is used to refer to either Address Bind or Port Bind. Bind Mode identifies whether a bind is Address Bind or Port Bind.

NAT Session - A NAT session is an association between a session as seen in the private realm and a session as seen in the public realm, by virtue of NAT translation. If a session in the private realm were to be represented as (PrivateSrcAddr, PrivateDstAddr, TransportProtocol, PrivateSrcPort, PrivateDstPort) and the same session in the public realm were to be represented as (PublicSrcAddr,

PublicDstAddr, TransportProtocol, PublicSrcPort, PublicDstPort), the NAT session will provide the translation glue between the two session representations. NAT sessions in the document are restricted to sessions based on TCP and UDP only. In the future, NAT sessions may be extended to be based on other transport protocols such as SCTP, UDP-lite and DCCP.

The terms 'local' and 'private' are used interchangeably throughout the document when referring to private networks, IP addresses, and ports. Likewise, the terms 'global' and 'public' are used interchangeably when referring to public networks, IP addresses, and ports.

Overview

NAT MIB is configurable on a per-interface basis and depends in several parts on the IF-MIB RFC2863.

NAT MIB requires that an interface for which NAT is configured be connected to either a private or a public realm. The realm association of the interface plays an important role in the definition of address maps for the interface. An address map entry identifies the orientation of the session (inbound or outbound to the interface) for which the entry may be used for NAT translation. The address map entry also identifies the end-point of the session that must be subject to translation. An SNMP Textual-Convention 'NatTranslationEntity' is defined to capture this important characteristic that combines session orientation and applicable session endpoint for translation.

An address map may consist of static or dynamic entries. NAT creates static binds from a static address map entry. Each static bind has a direct one-to-one relationship with a static address map entry. NAT creates dynamic binds from a dynamic address map entry upon seeing the first packet of a new session.

The following subsections define the key objects used in NAT MIB, their inter-relationship, and how to configure a NAT device using the MIB module.

natInterfaceTable

natInterfaceTable is defined in the MIB module to configure interface specific realm type and the NAT services enabled for the interface. natInterfaceTable is indexed by ifIndex and also includes interface specific NAT statistics.

The first step for an operator in configuring a NAT device is determining the interface over which NAT service is to be configured. When NAT service is operational, translated packets traverse the NAT device by ingressing on a private interface and egressing on a public interface or vice versa. An operator may configure the NAT service on either the public interface or the private interface in the traversal path.

As the next step, the operator must identify the NAT service(s) desired for the interface. The operator may configure one or more NAT services on the same interface. The MIB module identifies four types of NAT services: Basic NAT, NAPT, twice NAT and bidirectional NAT. These are NAT varieties as defined in RFC 2663 RFC2663. Note that RFC 3489 RFC3489 further classifies NAPT implementations based on the behavior exhibited by the NAPT devices from different vendors. However, the MIB module does not explicitly distinguish between the NAPT implementations. NAPT implementations may be distinguished between one another by monitoring the BIND and NAT Session objects generated by the NAT device as described in section 4.6.

natAddrMapTable

natAddrMapTable is defined in the MIB module to configure address maps on a per-interface basis. natAddrMapTable is indexed by the tuple of (ifIndex, natAddrMapIndex). The same table is also used to collect Statistics for the address map entries. Address maps are key to NAT configuration. An operator may configure one or more address map entries per interface. NAT looks up address map entries in the order in which they are defined to determine the translation function at the start of each new session traversing the interface. An address map may consist of static or dynamic entries. A static address map entry has a direct one-to-one relationship with binds. NAT will dynamically create binds from a dynamic address map entry.

The operator must be careful in selecting address map entries for an interface based on the interface realm-type and the type of NAT service desired. The operator can be amiss in the selection of address map entries when not paying attention to the associated interface characteristics defined in natInterfaceTable (described in section 4.1). For example, say the operator wishes to configure a NAPT map entry on an interface of a NAT device. If the operator chooses to configure the NAPT map entry on a public interface (i.e., interface realm-type is public), the operator should set the TranslationEntity of the NAPT address map entry to be outboundSrcEndPoint. On the other hand, if the operator chooses to configure the NAPT map entry on a private interface (i.e., interface realm-type is private), the operator should set the TranslationEntity of the NAPT address map entry to be InboundSrcEndPoint.

Default Timeouts, Protocol Table, and Other Scalars

DefTimeouts is defined in the MIB module to configure idle Bind timeout and IP protocol specific idle NAT session timeouts. The timeouts defined are global to the system and are not interface specific.

Protocol specific statistics are maintained in natProtocolTable, which is indexed by the protocol type.

The scalars natAddrBindNumberOfEntries and natAddrPortBindNumberOfEntries hold the number of entries that currently exist in the Address Bind and the Address Port Bind tables, respectively.

The generation of natPacketDiscard notifications can be configured by using the natNotifThrottlingInterval scalar MIB object.

natAddrBindTable and natAddrPortBindTable

Two Bind tables, natAddrBindTable and natAddrPortBindTable, are defined to hold the bind entries. Entries are derived from the address map table and are not configurable. natAddrBindTable contains Address Binds, and natAddrPortBindTable contains Address Port Binds. natAddrBindTable is indexed by the tuple of (ifIndex, LocalAddrType, LocalAddr). natAddrPortBindTable is indexed by the tuple of (ifIndex, LocalAddrType, LocalAddr, LocalPort, Protocol). These tables also maintain bind specific statistics. A Symmetric NAT will have no entries in the Bind tables.

natSessionTable

natSessionTable is defined to hold NAT session entries. NAT session entries are derived from NAT Binds (except in the case of Symmetric NAT) and are not configurable.

The NAT session provides the necessary translation glue between two session representations of the same end-to-end session; that is, a session as seen in the private realm and in the public realm. Session orientation (inbound or outbound) is determined from the orientation of the first packet traversing the NAT interface. Address map entries and bind entries on the interface determine whether a session is subject to NAT translation. One or both endpoints of a session may be subject to translation.

With the exception of symmetric NAT, all other NAT functions use end-point specific bind to perform individual end-point translations. Multiple NAT sessions would use the same bind as long as they share

the same endpoint. Symmetric NAT does not retain a consistent port bind across multiple sessions using the same endpoint. For this reason, the bind identifier for a NAT session in symmetric NAT is set to zero. natSessionTable is indexed by the tuple of (ifIndex, natSessionIndex). Statistics for NAT sessions are also maintained in the same table.

RFC 3489 NAPT Variations, NAT Session and Bind Tables

RFC3489 defines four variations of NAPT - Full Cone, Restricted Cone, Port Restricted Cone, and Symmetric NAT. These can be differentiated in the NAT MIB based on different values for the objects in the session and the bind tables, as indicated below.

In a Port Restricted Cone NAT, NAT Session objects will contain a non-zero PrivateSrcEPBindId object. Further, all address and port objects within a NAT session will have non-zero values (i.e., no wildcard matches).

An Address Restricted Cone NAT may have been implemented in the same way as a Port Restricted Cone NAT, except that the UDP NAT Sessions may use ANY match on PrivateDstPort and PublicDstPort objects; i.e., PrivateDstPort and PublicDstPort objects within a NAT session may be set to zero.

A Full Cone NAT may have also been implemented in the same way as a Port Restricted Cone NAT, except that the UDP NAT Sessions may use ANY match on PrivateDstAddr, PrivateDstPort, PublicDstAddr, and PublicDstPort objects. Within a NAT Session, all four of these objects may be set to zero. Alternately, all address and port objects within a NAT Session may have non-zero values, yet the TranslationEntity of the PrivateSrcEPBindId for the NAT Sessions may be set bi-directionally, i.e., as a bit mask of (outboundSrcEndPoint and inboundDstEndPoint) or (inboundSrcEndPoint and outboundDstEndPoint), depending on the interface realm type. Lastly, a Symmetric NAT does not maintain Port Bindings. As such, the NAT Session objects will have the PrivateSrcEPBindId set to zero.

Notifications

natPacketDiscard notifies the end user/manager of packets being discarded due to lack of address mappings.

Relation Among Tables

The association between the various NAT tables can be represented as follows:

                     Interface
                         |
                         |
                         |
                    Address map
                         |
                         |
                         |
    ----------------------------------------------
   |                                              |
   |                                              |
   |                                              |

Address Bind Port Bind

   |                                              |
   |                                              |
   |                                              |
    ----------------------------------------------
                         |
                         |
                         |
                     NAT Session

All NAT functions, with the exception of Symmetric NAT, use Bind(s) to provide the glue necessary for a NAT Session. natSessionPrivateSrcEPBindId and natSessionPrivateDstEPBindId objects represent the endpoint Binds used by NAT Sessions.

Configuration via the MIB

Sections 4.1 and 4.2 and part of section 4.3 refer to objects that are configurable on a NAT device. NAT derives Address Bind and Address Port Bind entries from the Address Map table. Hence, an Address Bind or an Address Port Bind entry must not exist without an associated entry in the Address Map table.

Further, NAT derives NAT session entries from NAT Binds, except in the case of symmetric NAT, which derives translation parameters for a NAT session directly from an address map entry. Hence, with the exception of Symmetric NAT, a NAT session entry must not exist in the NAT Session table without a corresponding bind.

A Management station may use the following steps to configure entries in the NAT-MIB:

- Create an entry in the natInterfaceTable specifying the value of

  ifIndex as the interface index of the interface on which NAT is
  being configured.  Specify appropriate values, as applicable, for
  the other objects (e.g., natInterfaceRealm,
  natInterfaceServiceType) in the table (refer to Section 4.1).

- Create one or more address map entries sequentially in reduced

  order of priority in the natAddrMapTable, specifying the value of
  ifIndex to be the same for all entries.  The ifIndex specified
  would be the same as that specified for natInterfaceTable (refer
  to Section 4.2).

- Configure the maximum permitted idle time duration for BINDs and

  TCP, UDP, and ICMP protocol sessions by setting the relevant
  scalars in natDefTimeouts object (refer to Section 4.3).

4.10. Relationship to Interface MIB

The natInterfaceTable specifies the NAT configuration attributes on each interface. The concept of "interface" is as defined by InterfaceIndex/ifIndex of the IETF Interfaces MIB RFC2863.

Definitions

This MIB module IMPORTs objects from RFCs 2578 RFC2578, 2579 RFC2579, 2580 RFC2580, 2863 RFC2863, 3411 RFC3411, and 4001 RFC4001. It also refers to information in RFCs 792 RFC792, 2463 RFC2463, and 3413 RFC3413.

NAT-MIB DEFINITIONS ::= BEGIN

IMPORTS

 MODULE-IDENTITY,
 OBJECT-TYPE,
 Integer32,
 Unsigned32,
 Gauge32,
 Counter64,
 TimeTicks,
 mib-2,
 NOTIFICATION-TYPE
         FROM SNMPv2-SMI
 TEXTUAL-CONVENTION,
 StorageType,
 RowStatus
         FROM SNMPv2-TC
 MODULE-COMPLIANCE,
 NOTIFICATION-GROUP,
 OBJECT-GROUP
         FROM SNMPv2-CONF
 ifIndex,
 ifCounterDiscontinuityGroup
         FROM IF-MIB
 SnmpAdminString
         FROM SNMP-FRAMEWORK-MIB
 InetAddressType,
 InetAddress,
 InetPortNumber
         FROM INET-ADDRESS-MIB;

natMIB MODULE-IDENTITY

 LAST-UPDATED "200503210000Z"
 ORGANIZATION "IETF Transport Area"
 CONTACT-INFO
          "
           Rohit
           Mascon Global Limited
           #59/2 100 ft Ring Road
           Banashankari II Stage
           Bangalore 560 070
           India
           Phone: +91 80 2679 6227
           Email: [email protected]
           P. Srisuresh
           Caymas Systems, Inc.
           1179-A North McDowell Blvd.
           Petaluma, CA 94954
           Tel: (707) 283-5063
           Email: [email protected]
           Rajiv Raghunarayan
           Cisco Systems Inc.
           170 West Tasman Drive
           San Jose, CA 95134
           Phone: +1 408 853 9612
           Email: [email protected]
           Nalinaksh Pai
           Cisco Systems, Inc.
           Prestige Waterford
           No. 9, Brunton Road
           Bangalore - 560 025
           India
           Phone: +91 80 532 1300
           Email: [email protected]
           Cliff Wang
           Information Security
           Bank One Corp
           1111 Polaris Pkwy
           Columbus, OH 43240
           Phone: +1 614 213 6117
           Email: [email protected]
         "
 DESCRIPTION
         "This MIB module defines the generic managed objects
          for NAT.
          Copyright (C) The Internet Society (2005).  This version
          of this MIB module is part of RFC 4008;  see the RFC
          itself for full legal notices."
 REVISION     "200503210000Z"  -- 21th March 2005
 DESCRIPTION
         "Initial version, published as RFC 4008."
 ::= { mib-2 123 }

natMIBObjects OBJECT IDENTIFIER ::= { natMIB 1 }

NatProtocolType ::= TEXTUAL-CONVENTION

   STATUS       current
   DESCRIPTION
           "A list of protocols that support the network
            address translation.  Inclusion of the values is
            not intended to imply that those protocols
            need to be supported.  Any change in this
            TEXTUAL-CONVENTION should also be reflected in
            the definition of NatProtocolMap, which is a
            BITS representation of this."
   SYNTAX   INTEGER {
                 none (1),  -- not specified
                 other (2), -- none of the following
                 icmp (3),
                 udp (4),
                 tcp (5)
              }

NatProtocolMap ::= TEXTUAL-CONVENTION

   STATUS       current
   DESCRIPTION
           "A bitmap of protocol identifiers that support
            the network address translation.  Any change
            in this TEXTUAL-CONVENTION should also be
            reflected in the definition of NatProtocolType."
   SYNTAX   BITS {
              other (0),
              icmp (1),
              udp (2),
              tcp (3)
            }

NatAddrMapId ::= TEXTUAL-CONVENTION

   DISPLAY-HINT "d"
   STATUS current
   DESCRIPTION
           "A unique id that is assigned to each address map
            by a NAT enabled device."
   SYNTAX   Unsigned32 (1..4294967295)

NatBindIdOrZero ::= TEXTUAL-CONVENTION

   DISPLAY-HINT "d"
   STATUS current
   DESCRIPTION
           "A unique id that is assigned to each bind by
            a NAT enabled device.  The bind id will be zero
            in the case of a Symmetric NAT."
   SYNTAX   Unsigned32 (0..4294967295)

NatBindId ::= TEXTUAL-CONVENTION

   DISPLAY-HINT "d"
   STATUS current
   DESCRIPTION
           "A unique id that is assigned to each bind by
            a NAT enabled device."
   SYNTAX   Unsigned32 (1..4294967295)

NatSessionId ::= TEXTUAL-CONVENTION

   DISPLAY-HINT "d"
   STATUS current
   DESCRIPTION
           "A unique id that is assigned to each session by
            a NAT enabled device."
   SYNTAX   Unsigned32 (1..4294967295)

NatBindMode ::= TEXTUAL-CONVENTION

   STATUS current
   DESCRIPTION
           "An indication of whether the bind is
            an address bind or an address port bind."
   SYNTAX   INTEGER {
                 addressBind (1),
                 addressPortBind (2)
            }

NatAssociationType ::= TEXTUAL-CONVENTION

   STATUS current
   DESCRIPTION
           "An indication of whether the association is
            static or dynamic."
   SYNTAX   INTEGER {
                 static (1),
                 dynamic (2)
            }

NatTranslationEntity ::= TEXTUAL-CONVENTION

   STATUS       current
   DESCRIPTION
           "An indication of a) the direction of a session for
            which an address map entry, address bind or port
            bind is applicable, and b) the entity (source or
            destination) within the session that is subject to
            translation."
   SYNTAX   BITS {
              inboundSrcEndPoint (0),
              outboundDstEndPoint(1),
              inboundDstEndPoint (2),
              outboundSrcEndPoint(3)
            }

-- -- Default Values for the Bind and NAT Protocol Timers --

natDefTimeouts OBJECT IDENTIFIER ::= { natMIBObjects 1 }

natNotifCtrl OBJECT IDENTIFIER ::= { natMIBObjects 2 }

-- -- Address Bind and Port Bind related NAT configuration --

natBindDefIdleTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (0..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default Bind (Address Bind or Port Bind) idle
         timeout parameter.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 0 }
::= { natDefTimeouts 1 }

-- -- UDP related NAT configuration --

natUdpDefIdleTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (1..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default UDP idle timeout parameter.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 300 }
::= { natDefTimeouts 2 }

-- -- ICMP related NAT configuration --

natIcmpDefIdleTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (1..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default ICMP idle timeout parameter.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 300 }
::= { natDefTimeouts 3 }

-- -- Other protocol parameters --

natOtherDefIdleTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (1..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default idle timeout parameter for protocols
         represented by the value other (2) in
         NatProtocolType.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 60 }
::= { natDefTimeouts 4 }

-- -- TCP related NAT Timers --

natTcpDefIdleTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (1..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default time interval that a NAT session for an
         established TCP connection is allowed to remain
         valid without any activity on the TCP connection.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 86400 }
::= { natDefTimeouts 5 }

natTcpDefNegTimeout OBJECT-TYPE

SYNTAX     Unsigned32  (1..4294967295)
UNITS      "seconds"
MAX-ACCESS read-write
STATUS     current
DESCRIPTION
        "The default time interval that a NAT session for a TCP
         connection that is not in the established state
         is allowed to remain valid without any activity on
         the TCP connection.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system."
DEFVAL { 60 }
::= { natDefTimeouts 6 }

natNotifThrottlingInterval OBJECT-TYPE

SYNTAX      Integer32 (0 | 5..3600)
UNITS       "seconds"
MAX-ACCESS  read-write
STATUS      current
DESCRIPTION
        "This object controls the generation of the
         natPacketDiscard notification.
         If this object has a value of zero, then no
         natPacketDiscard notifications will be transmitted by the
         agent.
         If this object has a non-zero value, then the agent must
         not generate more than one natPacketDiscard
         'notification-event' in the indicated period, where a
         'notification-event' is the generation of a single
         notification PDU type to a list of notification
         destinations.  If additional NAT packets are discarded
         within the throttling period, then notification-events
         for these changes must be suppressed by the agent until
         the current throttling period expires.
         If natNotifThrottlingInterval notification generation
         is enabled, the suggested default throttling period is
         60 seconds, but generation of the natPacketDiscard
         notification should be disabled by default.
         If the agent is capable of storing non-volatile
         configuration, then the value of this object must be
         restored after a re-initialization of the management
         system.
         The actual transmission of notifications is controlled
         via the MIB modules in RFC 3413."
DEFVAL { 0 }
::= { natNotifCtrl 1 }

-- -- The NAT Interface Table --

natInterfaceTable OBJECT-TYPE

SYNTAX      SEQUENCE OF NatInterfaceEntry
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This table specifies the attributes for interfaces on a
         device supporting NAT function."
::= { natMIBObjects 3 }

natInterfaceEntry OBJECT-TYPE

SYNTAX      NatInterfaceEntry
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "Each entry in the natInterfaceTable holds a set of
         parameters for an interface, instantiated by
         ifIndex.  Therefore, the interface index must have been
         assigned, according to the applicable procedures,
         before it can be meaningfully used.
         Generally, this means that the interface must exist.
         When natStorageType is of type nonVolatile, however,
         this may reflect the configuration for an interface whose
         ifIndex has been assigned but for which the supporting
         implementation is not currently present."
INDEX   { ifIndex }
::= { natInterfaceTable 1 }

NatInterfaceEntry ::= SEQUENCE {

natInterfaceRealm            INTEGER,
natInterfaceServiceType      BITS,
natInterfaceInTranslates     Counter64,
natInterfaceOutTranslates    Counter64,
natInterfaceDiscards         Counter64,
natInterfaceStorageType      StorageType,
natInterfaceRowStatus        RowStatus

}

natInterfaceRealm OBJECT-TYPE

SYNTAX     INTEGER {
               private (1),
               public (2)
           }
MAX-ACCESS read-create
STATUS     current
DESCRIPTION
        "This object identifies whether this interface is
         connected to the private or the public realm."
DEFVAL  { public }
::= { natInterfaceEntry 1 }

natInterfaceServiceType OBJECT-TYPE

SYNTAX  BITS {
            basicNat (0),
            napt (1),
            bidirectionalNat (2),
            twiceNat (3)
        }
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "An indication of the direction in which new sessions
         are permitted and the extent of translation done within
         the IP and transport headers."
::= { natInterfaceEntry 2 }

natInterfaceInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "Number of packets received on this interface that
         were translated.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natInterfaceEntry 3 }

natInterfaceOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "Number of translated packets that were sent out this
         interface.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natInterfaceEntry 4 }

natInterfaceDiscards OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "Number of packets that had to be rejected/dropped due to
         a lack of resources for this interface.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
 ::= { natInterfaceEntry 5 }

natInterfaceStorageType OBJECT-TYPE

SYNTAX      StorageType
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "The storage type for this conceptual row.
         Conceptual rows having the value 'permanent'
         need not allow write-access to any columnar objects
         in the row."
REFERENCE
        "Textual Conventions for SMIv2, Section 2."
DEFVAL { nonVolatile }
::= { natInterfaceEntry 6 }

natInterfaceRowStatus OBJECT-TYPE

SYNTAX      RowStatus
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "The status of this conceptual row.
         Until instances of all corresponding columns are
         appropriately configured, the value of the
         corresponding instance of the natInterfaceRowStatus
         column is 'notReady'.
         In particular, a newly created row cannot be made
         active until the corresponding instance of
         natInterfaceServiceType has been set.
         None of the objects in this row may be modified
         while the value of this object is active(1)."
REFERENCE
        "Textual Conventions for SMIv2, Section 2."
::= { natInterfaceEntry 7 }

-- -- The Address Map Table --

natAddrMapTable OBJECT-TYPE

SYNTAX      SEQUENCE OF NatAddrMapEntry
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This table lists address map parameters for NAT."
::= { natMIBObjects 4 }

natAddrMapEntry OBJECT-TYPE

SYNTAX      NatAddrMapEntry
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This entry represents an address map to be used for
         NAT and contributes to the dynamic and/or static
         address mapping tables of the NAT device."
INDEX   { ifIndex, natAddrMapIndex }
::= { natAddrMapTable 1 }

NatAddrMapEntry ::= SEQUENCE {

natAddrMapIndex                 NatAddrMapId,
natAddrMapName                  SnmpAdminString,
natAddrMapEntryType             NatAssociationType,
natAddrMapTranslationEntity     NatTranslationEntity,
natAddrMapLocalAddrType         InetAddressType,
natAddrMapLocalAddrFrom         InetAddress,
natAddrMapLocalAddrTo           InetAddress,
natAddrMapLocalPortFrom         InetPortNumber,
natAddrMapLocalPortTo           InetPortNumber,
natAddrMapGlobalAddrType        InetAddressType,
natAddrMapGlobalAddrFrom        InetAddress,
natAddrMapGlobalAddrTo          InetAddress,
natAddrMapGlobalPortFrom        InetPortNumber,
natAddrMapGlobalPortTo          InetPortNumber,
natAddrMapProtocol              NatProtocolMap,
natAddrMapInTranslates          Counter64,
natAddrMapOutTranslates         Counter64,
natAddrMapDiscards              Counter64,
natAddrMapAddrUsed              Gauge32,
natAddrMapStorageType           StorageType,
natAddrMapRowStatus             RowStatus

}

natAddrMapIndex OBJECT-TYPE

SYNTAX      NatAddrMapId
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "Along with ifIndex, this object uniquely
         identifies an entry in the natAddrMapTable.
         Address map entries are applied in the order
         specified by natAddrMapIndex."
::= { natAddrMapEntry 1 }

natAddrMapName OBJECT-TYPE

SYNTAX      SnmpAdminString (SIZE(1..32))
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "Name identifying all map entries in the table associated
         with the same interface.  All map entries with the same
         ifIndex MUST have the same map name."
::= { natAddrMapEntry 2 }

natAddrMapEntryType OBJECT-TYPE

SYNTAX      NatAssociationType
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This parameter can be used to set up static
         or dynamic address maps."
::= { natAddrMapEntry 3 }

natAddrMapTranslationEntity OBJECT-TYPE

SYNTAX      NatTranslationEntity
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "The end-point entity (source or destination) in
         inbound or outbound sessions (i.e., first packets) that
         may be translated by an address map entry.
         Session direction (inbound or outbound) is
         derived from the direction of the first packet
         of a session traversing a NAT interface.
         NAT address (and Transport-ID) maps may be defined
         to effect inbound or outbound sessions.
         Traditionally, address maps for Basic NAT and NAPT are
         configured on a public interface for outbound sessions,
         effecting translation of source end-point.  The value of
         this object must be set to outboundSrcEndPoint for
         those interfaces.
         Alternately, if address maps for Basic NAT and NAPT were
         to be configured on a private interface, the desired
         value for this object for the map entries
         would be inboundSrcEndPoint (i.e., effecting translation
         of source end-point for inbound sessions).
         If TwiceNAT were to be configured on a private interface,
         the desired value for this object for the map entries
         would be a bitmask of inboundSrcEndPoint and
         inboundDstEndPoint."
::= { natAddrMapEntry 4 }

natAddrMapLocalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrMapLocalAddrFrom and natAddrMapLocalAddrTo."
::= { natAddrMapEntry 5 }

natAddrMapLocalAddrFrom OBJECT-TYPE

SYNTAX      InetAddress
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the first IP address of the range
         of IP addresses mapped by this translation entry.  The
         value of this object must be less than or equal to the
         value of the natAddrMapLocalAddrTo object.
         The type of this address is determined by the value of
         the natAddrMapLocalAddrType object."
::= { natAddrMapEntry 6 }

natAddrMapLocalAddrTo OBJECT-TYPE

SYNTAX      InetAddress
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the last IP address of the range of
         IP addresses mapped by this translation entry.  If only
         a single address is being mapped, the value of this object
         is equal to the value of natAddrMapLocalAddrFrom.  For a
         static NAT, the number of addresses in the range defined
         by natAddrMapLocalAddrFrom and natAddrMapLocalAddrTo must
         be equal to the number of addresses in the range defined by
         natAddrMapGlobalAddrFrom and natAddrMapGlobalAddrTo.
         The value of this object must be greater than or equal to
         the value of the natAddrMapLocalAddrFrom object.
         The type of this address is determined by the value of
         the natAddrMapLocalAddrType object."
::= { natAddrMapEntry 7 }

natAddrMapLocalPortFrom OBJECT-TYPE

SYNTAX      InetPortNumber
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "If this conceptual row describes a Basic NAT address
         mapping, then the value of this object must be zero.  If
         this conceptual row describes NAPT, then the value of
         this object specifies the first port number in the range
         of ports being mapped.
         The value of this object must be less than or equal to the
         value of the natAddrMapLocalPortTo object.  If the
         translation specifies a single port, then the value of this
         object is equal to the value of natAddrMapLocalPortTo."
DEFVAL { 0 }
::= { natAddrMapEntry 8 }

natAddrMapLocalPortTo OBJECT-TYPE

SYNTAX      InetPortNumber
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "If this conceptual row describes a Basic NAT address
         mapping, then the value of this object must be zero.  If
         this conceptual row describes NAPT, then the value of
         this object specifies the last port number in the range
         of ports being mapped.
         The value of this object must be greater than or equal to
         the value of the natAddrMapLocalPortFrom object.  If the
         translation specifies a single port, then the value of this
         object is equal to the value of natAddrMapLocalPortFrom."
DEFVAL { 0 }
::= { natAddrMapEntry 9 }

natAddrMapGlobalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrMapGlobalAddrFrom and natAddrMapGlobalAddrTo."
::= { natAddrMapEntry 10 }

natAddrMapGlobalAddrFrom OBJECT-TYPE

SYNTAX      InetAddress
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the first IP address of the range of
         IP addresses being mapped to.  The value of this object
         must be less than or equal to the value of the
         natAddrMapGlobalAddrTo object.
         The type of this address is determined by the value of
         the natAddrMapGlobalAddrType object."
::= { natAddrMapEntry 11 }

natAddrMapGlobalAddrTo OBJECT-TYPE

SYNTAX      InetAddress
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies the last IP address of the range of
         IP addresses being mapped to.  If only a single address is
         being mapped to, the value of this object is equal to the
         value of natAddrMapGlobalAddrFrom.  For a static NAT, the
         number of addresses in the range defined by
         natAddrMapGlobalAddrFrom and natAddrMapGlobalAddrTo must be
         equal to the number of addresses in the range defined by
         natAddrMapLocalAddrFrom and natAddrMapLocalAddrTo.
         The value of this object must be greater than or equal to
         the value of the natAddrMapGlobalAddrFrom object.
         The type of this address is determined by the value of
         the natAddrMapGlobalAddrType object."
::= { natAddrMapEntry 12 }

natAddrMapGlobalPortFrom OBJECT-TYPE

SYNTAX      InetPortNumber
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "If this conceptual row describes a Basic NAT address
         mapping, then the value of this object must be zero.  If
         this conceptual row describes NAPT, then the value of
         this object specifies the first port number in the range
         of ports being mapped to.
         The value of this object must be less than or equal to the
         value of the natAddrMapGlobalPortTo object.  If the
         translation specifies a single port, then the value of this
         object is equal to the value natAddrMapGlobalPortTo."
DEFVAL { 0 }
::= { natAddrMapEntry 13 }

natAddrMapGlobalPortTo OBJECT-TYPE

SYNTAX      InetPortNumber
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "If this conceptual row describes a Basic NAT address
         mapping, then the value of this object must be zero.  If
         this conceptual row describes NAPT, then the value of this
         object specifies the last port number in the range of
         ports being mapped to.
         The value of this object must be greater than or equal to
         the value of the natAddrMapGlobalPortFrom object.  If the
         translation specifies a single port, then the value of this
         object is equal to the value of natAddrMapGlobalPortFrom."
DEFVAL { 0 }
::= { natAddrMapEntry 14 }

natAddrMapProtocol OBJECT-TYPE

SYNTAX      NatProtocolMap
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "This object specifies a bitmap of protocol identifiers."
::= { natAddrMapEntry 15 }

natAddrMapInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of inbound packets pertaining to this address
         map entry that were translated.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrMapEntry 16 }

natAddrMapOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of outbound packets pertaining to this
         address map entry that were translated.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrMapEntry 17 }

natAddrMapDiscards OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of packets pertaining to this address map
         entry that were dropped due to lack of addresses in the
         address pool identified by this address map.  The value of
         this object must always be zero in case of static
         address map.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrMapEntry 18 }

natAddrMapAddrUsed OBJECT-TYPE

SYNTAX     Gauge32
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of addresses pertaining to this address map
         that are currently being used from the NAT pool.
         The value of this object must always be zero in the case
         of a static address map."
::= { natAddrMapEntry 19 }

natAddrMapStorageType OBJECT-TYPE

SYNTAX      StorageType
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "The storage type for this conceptual row.
         Conceptual rows having the value 'permanent'
         need not allow write-access to any columnar objects
         in the row."
REFERENCE
        "Textual Conventions for SMIv2, Section 2."
DEFVAL { nonVolatile }
::= { natAddrMapEntry 20 }

natAddrMapRowStatus OBJECT-TYPE

SYNTAX      RowStatus
MAX-ACCESS  read-create
STATUS      current
DESCRIPTION
        "The status of this conceptual row.
         Until instances of all corresponding columns are
         appropriately configured, the value of the
         corresponding instance of the natAddrMapRowStatus
         column is 'notReady'.
         None of the objects in this row may be modified
         while the value of this object is active(1)."
REFERENCE
        "Textual Conventions for SMIv2, Section 2."
::= { natAddrMapEntry 21 }

-- -- Address Bind section --

natAddrBindNumberOfEntries OBJECT-TYPE

SYNTAX     Gauge32
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object maintains a count of the number of entries
         that currently exist in the natAddrBindTable."
::= { natMIBObjects 5 }

-- -- The NAT Address BIND Table --

natAddrBindTable OBJECT-TYPE

SYNTAX     SEQUENCE OF NatAddrBindEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "This table holds information about the currently
         active NAT BINDs."
::= { natMIBObjects 6 }

natAddrBindEntry OBJECT-TYPE

SYNTAX     NatAddrBindEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "Each entry in this table holds information about
         an active address BIND.  These entries are lost
         upon agent restart.
         This row has indexing which may create variables with
         more than 128 subidentifiers.  Implementers of this table
         must be careful not to create entries that would result
         in OIDs which exceed the 128 subidentifier limit.
         Otherwise, the information cannot be accessed using
         SNMPv1, SNMPv2c or SNMPv3."
INDEX   { ifIndex, natAddrBindLocalAddrType, natAddrBindLocalAddr }
::= { natAddrBindTable 1 }

NatAddrBindEntry ::= SEQUENCE {

natAddrBindLocalAddrType        InetAddressType,
natAddrBindLocalAddr            InetAddress,
natAddrBindGlobalAddrType       InetAddressType,
natAddrBindGlobalAddr           InetAddress,
natAddrBindId                   NatBindId,
natAddrBindTranslationEntity    NatTranslationEntity,
natAddrBindType                 NatAssociationType,
natAddrBindMapIndex             NatAddrMapId,
natAddrBindSessions             Gauge32,
natAddrBindMaxIdleTime          TimeTicks,
natAddrBindCurrentIdleTime      TimeTicks,
natAddrBindInTranslates         Counter64,
natAddrBindOutTranslates        Counter64

}

natAddrBindLocalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrBindLocalAddr."
::= { natAddrBindEntry 1 }

natAddrBindLocalAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "This object represents the private-realm specific network
         layer address, which maps to the public-realm address
         represented by natAddrBindGlobalAddr.
         The type of this address is determined by the value of
         the natAddrBindLocalAddrType object."
= { natAddrBindEntry 2 }

natAddrBindGlobalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-only
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrBindGlobalAddr."
::= { natAddrBindEntry 3 }

natAddrBindGlobalAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents the public-realm network layer
         address that maps to the private-realm network layer
         address represented by natAddrBindLocalAddr.
         The type of this address is determined by the value of
         the natAddrBindGlobalAddrType object."
::= { natAddrBindEntry 4 }

natAddrBindId OBJECT-TYPE

SYNTAX     NatBindId
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents a bind id that is dynamically
         assigned to each bind by a NAT enabled device.  Each
         bind is represented by a bind id that is
         unique across both, the natAddrBindTable and the
         natAddrPortBindTable."
::= { natAddrBindEntry 5 }

natAddrBindTranslationEntity OBJECT-TYPE

SYNTAX     NatTranslationEntity
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents the direction of sessions
         for which this bind is applicable and the endpoint entity
         (source or destination) within the sessions that is
         subject to translation using the BIND.
         Orientation of the bind can be a superset of
         translationEntity of the address map entry which
         forms the basis for this bind.
         For example, if the translationEntity of an
         address map entry is outboundSrcEndPoint, the
         translationEntity of a bind derived from this
         map entry may either be outboundSrcEndPoint or
         it may be bidirectional (a bitmask of
         outboundSrcEndPoint and inboundDstEndPoint)."
::= { natAddrBindEntry 6 }

natAddrBindType OBJECT-TYPE

SYNTAX     NatAssociationType
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates whether the bind is static or
         dynamic."
::= { natAddrBindEntry 7 }

natAddrBindMapIndex OBJECT-TYPE

SYNTAX     NatAddrMapId
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object is a pointer to the natAddrMapTable entry
         (and the parameters of that entry) which was used in
         creating this BIND.  This object, in conjunction with the
         ifIndex (which identifies a unique addrMapName) points to
         a unique entry in the natAddrMapTable."
::= { natAddrBindEntry 8 }

natAddrBindSessions OBJECT-TYPE

SYNTAX     Gauge32
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "Number of sessions currently using this BIND."
::= { natAddrBindEntry 9 }

natAddrBindMaxIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates the maximum time for
         which this bind can be idle with no sessions
         attached to it.
         The value of this object is of relevance only for
         dynamic NAT."
::= { natAddrBindEntry 10 }

natAddrBindCurrentIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "At any given instance, this object indicates the
         time that this bind has been idle without any sessions
         attached to it.
         The value of this object is of relevance only for
         dynamic NAT."
::= { natAddrBindEntry 11 }

natAddrBindInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of inbound packets that were successfully
         translated by using this bind entry.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrBindEntry 12 }

natAddrBindOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of outbound packets that were successfully
         translated using this bind entry.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrBindEntry 13 }

-- -- Address Port Bind section --

natAddrPortBindNumberOfEntries OBJECT-TYPE

SYNTAX     Gauge32
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object maintains a count of the number of entries
         that currently exist in the natAddrPortBindTable."
::= { natMIBObjects 7 }

-- -- The NAT Address Port Bind Table --

natAddrPortBindTable OBJECT-TYPE

SYNTAX     SEQUENCE OF NatAddrPortBindEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "This table holds information about the currently
         active NAPT BINDs."
::= { natMIBObjects 8 }

natAddrPortBindEntry OBJECT-TYPE

SYNTAX     NatAddrPortBindEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "Each entry in the this table holds information
         about a NAPT bind that is currently active.
         These entries are lost upon agent restart.
         This row has indexing which may create variables with
         more than 128 subidentifiers.  Implementers of this table
         must be careful not to create entries which would result
         in OIDs that exceed the 128 subidentifier limit.
         Otherwise, the information cannot be accessed using
         SNMPv1, SNMPv2c or SNMPv3."
INDEX   { ifIndex, natAddrPortBindLocalAddrType,
          natAddrPortBindLocalAddr, natAddrPortBindLocalPort,
          natAddrPortBindProtocol }
::= { natAddrPortBindTable 1 }

NatAddrPortBindEntry ::= SEQUENCE {

natAddrPortBindLocalAddrType        InetAddressType,
natAddrPortBindLocalAddr            InetAddress,
natAddrPortBindLocalPort            InetPortNumber,
natAddrPortBindProtocol             NatProtocolType,
natAddrPortBindGlobalAddrType       InetAddressType,
natAddrPortBindGlobalAddr           InetAddress,
natAddrPortBindGlobalPort           InetPortNumber,
natAddrPortBindId                   NatBindId,
natAddrPortBindTranslationEntity    NatTranslationEntity,
natAddrPortBindType                 NatAssociationType,
natAddrPortBindMapIndex             NatAddrMapId,
natAddrPortBindSessions             Gauge32,
natAddrPortBindMaxIdleTime          TimeTicks,
natAddrPortBindCurrentIdleTime      TimeTicks,
natAddrPortBindInTranslates         Counter64,
natAddrPortBindOutTranslates        Counter64

}

natAddrPortBindLocalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrPortBindLocalAddr."
::= { natAddrPortBindEntry 1 }

natAddrPortBindLocalAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "This object represents the private-realm specific network
         layer address which, in conjunction with
         natAddrPortBindLocalPort, maps to the public-realm
         network layer address and transport id represented by
         natAddrPortBindGlobalAddr and natAddrPortBindGlobalPort
         respectively.
         The type of this address is determined by the value of
         the natAddrPortBindLocalAddrType object."
::= { natAddrPortBindEntry 2 }

natAddrPortBindLocalPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "For a protocol value TCP or UDP, this object represents
         the private-realm specific port number.  On the other
         hand, for ICMP a bind is created only for query/response
         type ICMP messages such as ICMP echo, Timestamp, and
         Information request messages, and this object represents
         the private-realm specific identifier in the ICMP
         message, as defined in RFC 792 for ICMPv4 and in RFC
         2463 for ICMPv6.
         This object, together with natAddrPortBindProtocol,
         natAddrPortBindLocalAddrType, and natAddrPortBindLocalAddr,
         constitutes a session endpoint in the private realm.  A
         bind entry binds a private realm specific endpoint to a
         public realm specific endpoint, as represented by the
         tuple of (natAddrPortBindGlobalPort,
         natAddrPortBindProtocol, natAddrPortBindGlobalAddrType,
         and natAddrPortBindGlobalAddr)."
= { natAddrPortBindEntry 3 }

natAddrPortBindProtocol OBJECT-TYPE

SYNTAX      NatProtocolType
MAX-ACCESS  not-accessible
STATUS      current
DESCRIPTION
        "This object specifies a protocol identifier.  If the
         value of this object is none(1), then this bind entry
         applies to all IP traffic.  Any other value of this object
         specifies the class of IP traffic to which this BIND
         applies."
::= { natAddrPortBindEntry 4 }

natAddrPortBindGlobalAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-only
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natAddrPortBindGlobalAddr."
::= { natAddrPortBindEntry 5 }

natAddrPortBindGlobalAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents the public-realm specific network
         layer address that, in conjunction with
         natAddrPortBindGlobalPort, maps to the private-realm
         network layer address and transport id represented by
         natAddrPortBindLocalAddr and natAddrPortBindLocalPort,
         respectively.
         The type of this address is determined by the value of
         the natAddrPortBindGlobalAddrType object."
::= { natAddrPortBindEntry 6 }

natAddrPortBindGlobalPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "For a protocol value TCP or UDP, this object represents
         the public-realm specific port number.  On the other
         hand, for ICMP a bind is created only for query/response
         type ICMP messages such as ICMP echo, Timestamp, and
         Information request messages, and this object represents
         the public-realm specific identifier in the ICMP message,
         as defined in RFC 792 for ICMPv4 and in RFC 2463 for
         ICMPv6.
         This object, together with natAddrPortBindProtocol,
         natAddrPortBindGlobalAddrType, and
         natAddrPortBindGlobalAddr, constitutes a session endpoint
         in the public realm.  A bind entry binds a public realm
         specific endpoint to a private realm specific endpoint,
         as represented by the tuple of
          (natAddrPortBindLocalPort, natAddrPortBindProtocol,
           natAddrPortBindLocalAddrType, and
           natAddrPortBindLocalAddr)."
::= { natAddrPortBindEntry 7 }

natAddrPortBindId OBJECT-TYPE

SYNTAX     NatBindId
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents a bind id that is dynamically
         assigned to each bind by a NAT enabled device.  Each
         bind is represented by a unique bind id across both
         the natAddrBindTable and the natAddrPortBindTable."
::= { natAddrPortBindEntry 8 }

natAddrPortBindTranslationEntity OBJECT-TYPE

SYNTAX     NatTranslationEntity
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object represents the direction of sessions
         for which this bind is applicable and the entity
         (source or destination) within the sessions that is
         subject to translation with the BIND.
         Orientation of the bind can be a superset of the
         translationEntity of the address map entry that
         forms the basis for this bind.
         For example, if the translationEntity of an
         address map entry is outboundSrcEndPoint, the
         translationEntity of a bind derived from this
         map entry may either be outboundSrcEndPoint or
         may be bidirectional (a bitmask of
         outboundSrcEndPoint and inboundDstEndPoint)."
::= { natAddrPortBindEntry 9 }

natAddrPortBindType OBJECT-TYPE

SYNTAX     NatAssociationType
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates whether the bind is static or
         dynamic."
::= { natAddrPortBindEntry 10 }

natAddrPortBindMapIndex OBJECT-TYPE

SYNTAX     NatAddrMapId
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object is a pointer to the natAddrMapTable entry
         (and the parameters of that entry) used in
         creating this BIND.  This object, in conjunction with the
         ifIndex (which identifies a unique addrMapName), points
         to a unique entry in the natAddrMapTable."
::= { natAddrPortBindEntry 11 }

natAddrPortBindSessions OBJECT-TYPE

SYNTAX     Gauge32
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "Number of sessions currently using this BIND."
::= { natAddrPortBindEntry 12 }

natAddrPortBindMaxIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates the maximum time for
         which this bind can be idle without any sessions
         attached to it.
         The value of this object is of relevance
         only for dynamic NAT."
::= { natAddrPortBindEntry 13 }

natAddrPortBindCurrentIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "At any given instance, this object indicates the
         time that this bind has been idle without any sessions
         attached to it.
         The value of this object is of relevance
         only for dynamic NAT."
::= { natAddrPortBindEntry 14 }

natAddrPortBindInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of inbound packets that were translated as per
         this bind entry.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrPortBindEntry 15 }

natAddrPortBindOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of outbound packets that were translated as per
         this bind entry.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natAddrPortBindEntry 16 }

-- -- The Session Table --

natSessionTable OBJECT-TYPE

SYNTAX     SEQUENCE OF NatSessionEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "The (conceptual) table containing one entry for each
         NAT session currently active on this NAT device."
::= { natMIBObjects 9 }

natSessionEntry OBJECT-TYPE

SYNTAX     NatSessionEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "An entry (conceptual row) containing information
         about an active NAT session on this NAT device.
         These entries are lost upon agent restart."
INDEX   { ifIndex, natSessionIndex }
::= { natSessionTable 1 }

NatSessionEntry ::= SEQUENCE {

natSessionIndex                        NatSessionId,
natSessionPrivateSrcEPBindId           NatBindIdOrZero,
natSessionPrivateSrcEPBindMode         NatBindMode,
natSessionPrivateDstEPBindId           NatBindIdOrZero,
natSessionPrivateDstEPBindMode         NatBindMode,
natSessionDirection                    INTEGER,
natSessionUpTime                       TimeTicks,
natSessionAddrMapIndex                 NatAddrMapId,
natSessionProtocolType                 NatProtocolType,
natSessionPrivateAddrType              InetAddressType,
natSessionPrivateSrcAddr               InetAddress,
natSessionPrivateSrcPort               InetPortNumber,
natSessionPrivateDstAddr               InetAddress,
natSessionPrivateDstPort               InetPortNumber,
natSessionPublicAddrType               InetAddressType,
natSessionPublicSrcAddr                InetAddress,
natSessionPublicSrcPort                InetPortNumber,
natSessionPublicDstAddr                InetAddress,
natSessionPublicDstPort                InetPortNumber,
natSessionMaxIdleTime                  TimeTicks,
natSessionCurrentIdleTime              TimeTicks,
natSessionInTranslates                 Counter64,
natSessionOutTranslates                Counter64

}

natSessionIndex OBJECT-TYPE

SYNTAX     NatSessionId
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "The session ID for this NAT session."
::= { natSessionEntry 1 }

natSessionPrivateSrcEPBindId OBJECT-TYPE

SYNTAX     NatBindIdOrZero
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The bind id associated between private and public
         source end points.  In the case of Symmetric-NAT,
         this should be set to zero."
::= { natSessionEntry 2 }

natSessionPrivateSrcEPBindMode OBJECT-TYPE

SYNTAX     NatBindMode
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates whether the bind indicated
         by the object natSessionPrivateSrcEPBindId
         is an address bind or an address port bind."
::= { natSessionEntry 3 }

natSessionPrivateDstEPBindId OBJECT-TYPE

SYNTAX     NatBindIdOrZero
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The bind id associated between private and public
         destination end points."
::= { natSessionEntry 4 }

natSessionPrivateDstEPBindMode OBJECT-TYPE

SYNTAX     NatBindMode
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object indicates whether the bind indicated
         by the object natSessionPrivateDstEPBindId
         is an address bind or an address port bind."
::= { natSessionEntry 5 }

natSessionDirection OBJECT-TYPE

SYNTAX     INTEGER {
               inbound (1),
               outbound (2)
           }
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The direction of this session with respect to the
         local network.  'inbound' indicates that this session
         was initiated from the public network into the private
         network.  'outbound' indicates that this session was
         initiated from the private network into the public
         network."
::= { natSessionEntry 6 }

natSessionUpTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The up time of this session in one-hundredths of a
         second."
::= { natSessionEntry 7 }

natSessionAddrMapIndex OBJECT-TYPE

SYNTAX     NatAddrMapId
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "This object is a pointer to the natAddrMapTable entry
         (and the parameters of that entry) used in
         creating this session.  This object, in conjunction with
         the ifIndex (which identifies a unique addrMapName), points
         to a unique entry in the natAddrMapTable."
::= { natSessionEntry 8 }

natSessionProtocolType OBJECT-TYPE

SYNTAX     NatProtocolType
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The protocol type of this session."
::= { natSessionEntry 9 }

natSessionPrivateAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-only
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natSessionPrivateSrcAddr and natSessionPrivateDstAddr."
::= { natSessionEntry 10 }

natSessionPrivateSrcAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The source IP address of the session endpoint that
         lies in the private network.
         The value of this object must be zero only when the
         natSessionPrivateSrcEPBindId object has a zero value.
         When the value of this object is zero, the NAT session
         lookup will match any IP address to this field.
         The type of this address is determined by the value of
         the natSessionPrivateAddrType object."
::= { natSessionEntry 11 }

natSessionPrivateSrcPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "When the value of protocol is TCP or UDP, this object
         represents the source port in the first packet of session
         while in private-realm.  On the other hand, when the
         protocol is ICMP, a NAT session is created only for
         query/response type ICMP messages such as ICMP echo,
         Timestamp, and Information request messages, and this
         object represents the private-realm specific identifier
         in the ICMP message, as defined in RFC 792 for ICMPv4
         and in RFC 2463 for ICMPv6.
         The value of this object must be zero when the
         natSessionPrivateSrcEPBindId object has zero value
         and value of natSessionPrivateSrcEPBindMode is
         addressPortBind(2).  In such a case, the NAT session
         lookup will match any port number to this field.
         The value of this object must be zero when the object
         is not a representative field (SrcPort, DstPort, or
         ICMP identifier) of the session tuple in either the
         public realm or the private realm."
::= { natSessionEntry 12 }

natSessionPrivateDstAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The destination IP address of the session endpoint that
         lies in the private network.
         The value of this object must be zero when the
         natSessionPrivateDstEPBindId object has a zero value.
         In such a scenario, the NAT session lookup will match
         any IP address to this field.
         The type of this address is determined by the value of
         the natSessionPrivateAddrType object."
::= { natSessionEntry 13 }

natSessionPrivateDstPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "When the value of protocol is TCP or UDP, this object
         represents the destination port in the first packet
         of session while in private-realm.  On the other hand,
         when the protocol is ICMP, this object is not relevant
         and should be set to zero.
         The value of this object must be zero when the
         natSessionPrivateDstEPBindId object has a zero
         value and natSessionPrivateDstEPBindMode is set to
         addressPortBind(2).  In such a case, the NAT session
         lookup will match any port number to this field.
         The value of this object must be zero when the object
         is not a representative field (SrcPort, DstPort, or
         ICMP identifier) of the session tuple in either the
         public realm or the private realm."
::= { natSessionEntry 14 }

natSessionPublicAddrType OBJECT-TYPE

SYNTAX      InetAddressType
MAX-ACCESS  read-only
STATUS      current
DESCRIPTION
        "This object specifies the address type used for
         natSessionPublicSrcAddr and natSessionPublicDstAddr."
::= { natSessionEntry 15 }

natSessionPublicSrcAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The source IP address of the session endpoint that
         lies in the public network.
         The value of this object must be zero when the
         natSessionPrivateSrcEPBindId object has a zero value.
         In such a scenario, the NAT session lookup will match
         any IP address to this field.
         The type of this address is determined by the value of
         the natSessionPublicAddrType object."
::= { natSessionEntry 16 }

natSessionPublicSrcPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "When the value of protocol is TCP or UDP, this object
         represents the source port in the first packet of
         session while in public-realm.  On the other hand, when
         protocol is ICMP, a NAT session is created only for
         query/response type ICMP messages such as ICMP echo,
         Timestamp, and Information request messages, and this
         object represents the public-realm specific identifier
         in the ICMP message, as defined in RFC 792 for ICMPv4
         and in RFC 2463 for ICMPv6.
         The value of this object must be zero when the
         natSessionPrivateSrcEPBindId object has a zero value
         and natSessionPrivateSrcEPBindMode is set to
         addressPortBind(2).  In such a scenario, the NAT
         session lookup will match any port number to this
         field.
         The value of this object must be zero when the object
         is not a representative field (SrcPort, DstPort or
         ICMP identifier) of the session tuple in either the
         public realm or the private realm."
::= { natSessionEntry 17 }

natSessionPublicDstAddr OBJECT-TYPE

SYNTAX     InetAddress
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The destination IP address of the session endpoint that
         lies in the public network.
         The value of this object must be non-zero when the
         natSessionPrivateDstEPBindId object has a non-zero
         value.  If the value of this object and the
         corresponding natSessionPrivateDstEPBindId object value
         is zero, then the NAT session lookup will match any IP
         address to this field.
         The type of this address is determined by the value of
         the natSessionPublicAddrType object."
::= { natSessionEntry 18 }

natSessionPublicDstPort OBJECT-TYPE

SYNTAX     InetPortNumber
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "When the value of protocol is TCP or UDP, this object
         represents the destination port in the first packet of
         session while in public-realm.  On the other hand, when
         the protocol is ICMP, this object is not relevant for
         translation and should be zero.
         The value of this object must be zero when the
         natSessionPrivateDstEPBindId object has a zero value
         and natSessionPrivateDstEPBindMode is
         addressPortBind(2).  In such a scenario, the NAT
         session lookup will match any port number to this
         field.
         The value of this object must be zero when the object
         is not a representative field (SrcPort, DstPort, or
         ICMP identifier) of the session tuple in either the
         public realm or the private realm."
::= { natSessionEntry 19 }

natSessionMaxIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The max time for which this session can be idle
         without detecting a packet."
::= { natSessionEntry 20 }

natSessionCurrentIdleTime OBJECT-TYPE

SYNTAX     TimeTicks
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The time since a packet belonging to this session was
        last detected."
::= { natSessionEntry 21 }

natSessionInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of inbound packets that were translated for
         this session.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natSessionEntry 22 }

natSessionOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of outbound packets that were translated for
         this session.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natSessionEntry 23 }

-- -- The Protocol table --

natProtocolTable OBJECT-TYPE

SYNTAX     SEQUENCE OF NatProtocolEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "The (conceptual) table containing per protocol NAT
         statistics."
::= { natMIBObjects 10 }

natProtocolEntry OBJECT-TYPE

SYNTAX     NatProtocolEntry
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "An entry (conceptual row) containing NAT statistics
         pertaining to a particular protocol."
INDEX   { natProtocol }
::= { natProtocolTable 1 }

NatProtocolEntry ::= SEQUENCE {

natProtocol                 NatProtocolType,
natProtocolInTranslates     Counter64,
natProtocolOutTranslates    Counter64,
natProtocolDiscards         Counter64

}

natProtocol OBJECT-TYPE

SYNTAX     NatProtocolType
MAX-ACCESS not-accessible
STATUS     current
DESCRIPTION
        "This object represents the protocol pertaining to which
         parameters are reported."
::= { natProtocolEntry 1 }

natProtocolInTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of inbound packets pertaining to the protocol
         identified by natProtocol that underwent NAT.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natProtocolEntry 2 }

natProtocolOutTranslates OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of outbound packets pertaining to the protocol
         identified by natProtocol that underwent NAT.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
::= { natProtocolEntry 3 }

natProtocolDiscards OBJECT-TYPE

SYNTAX     Counter64
MAX-ACCESS read-only
STATUS     current
DESCRIPTION
        "The number of packets pertaining to the protocol
         identified by natProtocol that had to be
         rejected/dropped due to lack of resources.  These
         rejections could be due to session timeout, resource
         unavailability, lack of address space, etc.
         Discontinuities in the value of this counter can occur at
         reinitialization of the management system and at other
         times, as indicated by the value of
         ifCounterDiscontinuityTime on the relevant interface."
 ::= { natProtocolEntry 4 }

-- -- Notifications section --

natMIBNotifications OBJECT IDENTIFIER ::= { natMIB 0 }

-- -- Notifications --

natPacketDiscard NOTIFICATION-TYPE

OBJECTS { ifIndex }
STATUS  current
DESCRIPTION
        "This notification is generated when IP packets are
         discarded by the NAT function; e.g., due to lack of
         mapping space when NAT is out of addresses or ports.
         Note that the generation of natPacketDiscard
         notifications is throttled by the agent, as specified
         by the 'natNotifThrottlingInterval' object."
::= { natMIBNotifications 1 }

-- -- Conformance information. --

natMIBConformance OBJECT IDENTIFIER ::= { natMIB 2 }

natMIBGroups OBJECT IDENTIFIER ::= { natMIBConformance 1 } natMIBCompliances OBJECT IDENTIFIER ::= { natMIBConformance 2 }

-- -- Units of conformance --

natConfigGroup OBJECT-GROUP

OBJECTS { natInterfaceRealm,
          natInterfaceServiceType,
          natInterfaceStorageType,
          natInterfaceRowStatus,
          natAddrMapName,
          natAddrMapEntryType,
          natAddrMapTranslationEntity,
          natAddrMapLocalAddrType,
          natAddrMapLocalAddrFrom,
          natAddrMapLocalAddrTo,
          natAddrMapLocalPortFrom,
          natAddrMapLocalPortTo,
          natAddrMapGlobalAddrType,
          natAddrMapGlobalAddrFrom,
          natAddrMapGlobalAddrTo,
          natAddrMapGlobalPortFrom,
          natAddrMapGlobalPortTo,
          natAddrMapProtocol,
          natAddrMapStorageType,
          natAddrMapRowStatus,
          natBindDefIdleTimeout,
          natUdpDefIdleTimeout,
          natIcmpDefIdleTimeout,
          natOtherDefIdleTimeout,
          natTcpDefIdleTimeout,
          natTcpDefNegTimeout,
          natNotifThrottlingInterval }
STATUS  current
DESCRIPTION
        "A collection of configuration-related information
         required to support management of devices supporting
         NAT."
::= { natMIBGroups 1 }

natTranslationGroup OBJECT-GROUP

OBJECTS { natAddrBindNumberOfEntries,
          natAddrBindGlobalAddrType,
          natAddrBindGlobalAddr,
          natAddrBindId,
          natAddrBindTranslationEntity,
          natAddrBindType,
          natAddrBindMapIndex,
          natAddrBindSessions,
          natAddrBindMaxIdleTime,
          natAddrBindCurrentIdleTime,
          natAddrBindInTranslates,
          natAddrBindOutTranslates,
          natAddrPortBindNumberOfEntries,
          natAddrPortBindGlobalAddrType,
          natAddrPortBindGlobalAddr,
          natAddrPortBindGlobalPort,
          natAddrPortBindId,
          natAddrPortBindTranslationEntity,
          natAddrPortBindType,
          natAddrPortBindMapIndex,
          natAddrPortBindSessions,
          natAddrPortBindMaxIdleTime,
          natAddrPortBindCurrentIdleTime,
          natAddrPortBindInTranslates,
          natAddrPortBindOutTranslates,
          natSessionPrivateSrcEPBindId,
          natSessionPrivateSrcEPBindMode,
          natSessionPrivateDstEPBindId,
          natSessionPrivateDstEPBindMode,
          natSessionDirection,
          natSessionUpTime,
          natSessionAddrMapIndex,
          natSessionProtocolType,
          natSessionPrivateAddrType,
          natSessionPrivateSrcAddr,
          natSessionPrivateSrcPort,
          natSessionPrivateDstAddr,
          natSessionPrivateDstPort,
          natSessionPublicAddrType,
          natSessionPublicSrcAddr,
          natSessionPublicSrcPort,
          natSessionPublicDstAddr,
          natSessionPublicDstPort,
          natSessionMaxIdleTime,
          natSessionCurrentIdleTime,
          natSessionInTranslates,
          natSessionOutTranslates }
STATUS  current
DESCRIPTION
        "A collection of BIND-related objects required to support
         management of devices supporting NAT."
::= { natMIBGroups 2 }

natStatsInterfaceGroup OBJECT-GROUP

OBJECTS { natInterfaceInTranslates,
          natInterfaceOutTranslates,
          natInterfaceDiscards }
STATUS  current
DESCRIPTION
        "A collection of NAT statistics associated with the
         interface on which NAT is configured, to aid
         troubleshooting/monitoring of the NAT operation."
::= { natMIBGroups 3 }

natStatsProtocolGroup OBJECT-GROUP

OBJECTS { natProtocolInTranslates,
          natProtocolOutTranslates,
          natProtocolDiscards }
STATUS  current
DESCRIPTION
        "A collection of protocol specific NAT statistics,
         to aid troubleshooting/monitoring of NAT operation."
::= { natMIBGroups 4 }

natStatsAddrMapGroup OBJECT-GROUP

OBJECTS { natAddrMapInTranslates,
          natAddrMapOutTranslates,
          natAddrMapDiscards,
          natAddrMapAddrUsed }
STATUS  current
DESCRIPTION
        "A collection of address map specific NAT statistics,
         to aid troubleshooting/monitoring of NAT operation."
::= { natMIBGroups 5 }

natMIBNotificationGroup NOTIFICATION-GROUP

NOTIFICATIONS { natPacketDiscard }
STATUS        current
DESCRIPTION
        "A collection of notifications generated by
        devices supporting this MIB."
::= { natMIBGroups 6 }

-- -- Compliance statements --

natMIBFullCompliance MODULE-COMPLIANCE

STATUS  current
DESCRIPTION
        "When this MIB is implemented with support for
         read-create, then such an implementation can claim
         full compliance.  Such devices can then be both
         monitored and configured with this MIB.
         The following index objects cannot be added as OBJECT
         clauses but nevertheless have the compliance
         requirements:
             "
         -- OBJECT  natAddrBindLocalAddrType
         -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrBindLocalAddr
         -- SYNTAX  InetAddress (SIZE(4|16))
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrPortBindLocalAddrType
         -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrPortBindLocalAddr
         -- SYNTAX  InetAddress (SIZE(4|16))
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
MODULE IF-MIB -- The interfaces MIB, RFC2863
  MANDATORY-GROUPS {
    ifCounterDiscontinuityGroup
  }
MODULE  -- this module
  MANDATORY-GROUPS { natConfigGroup, natTranslationGroup,
                     natStatsInterfaceGroup }
  GROUP       natStatsProtocolGroup
  DESCRIPTION
           "This group is optional."
  GROUP       natStatsAddrMapGroup
  DESCRIPTION
           "This group is optional."
  GROUP       natMIBNotificationGroup
  DESCRIPTION
           "This group is optional."
  OBJECT  natAddrMapLocalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrMapLocalAddrFrom
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrMapLocalAddrTo
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrFrom
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrTo
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrBindGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrBindGlobalAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrPortBindGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natAddrPortBindGlobalAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPrivateAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPrivateSrcAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPrivateDstAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPublicAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPublicSrcAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
  OBJECT  natSessionPublicDstAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support
           for IPv4 and IPv6."
::= { natMIBCompliances 1 }

natMIBReadOnlyCompliance MODULE-COMPLIANCE

STATUS  current
DESCRIPTION
        "When this MIB is implemented without support for
         read-create (i.e., in read-only mode), then such an
         implementation can claim read-only compliance.
         Such a device can then be monitored but cannot be
         configured with this MIB.
         The following index objects cannot be added as OBJECT
         clauses but nevertheless have the compliance
         requirements:
         "
         -- OBJECT  natAddrBindLocalAddrType
         -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrBindLocalAddr
         -- SYNTAX  InetAddress (SIZE(4|16))
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrPortBindLocalAddrType
         -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
         -- OBJECT  natAddrPortBindLocalAddr
         -- SYNTAX  InetAddress (SIZE(4|16))
         -- DESCRIPTION
         --         "An implementation is required to support
         --          global IPv4 and/or IPv6 addresses, depending
         --          on its support for IPv4 and IPv6."
MODULE IF-MIB -- The interfaces MIB, RFC2863
  MANDATORY-GROUPS {
    ifCounterDiscontinuityGroup
  }
MODULE  -- this module
  MANDATORY-GROUPS { natConfigGroup, natTranslationGroup,
                     natStatsInterfaceGroup }
  GROUP       natStatsProtocolGroup
  DESCRIPTION
           "This group is optional."
  GROUP       natStatsAddrMapGroup
  DESCRIPTION
           "This group is optional."
  GROUP       natMIBNotificationGroup
  DESCRIPTION
           "This group is optional."
  OBJECT natInterfaceRowStatus
  SYNTAX RowStatus { active(1) }
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required, and active is the only
           status that needs to be supported."
  OBJECT  natAddrMapLocalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT  natAddrMapLocalAddrFrom
  SYNTAX  InetAddress (SIZE(4|16))
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT  natAddrMapLocalAddrTo
  SYNTAX  InetAddress (SIZE(4|16))
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrFrom
  SYNTAX  InetAddress (SIZE(4|16))
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT  natAddrMapGlobalAddrTo
  SYNTAX  InetAddress (SIZE(4|16))
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required.  An implementation is
           required to support global IPv4 and/or IPv6 addresses,
           depending on its support for IPv4 and IPv6."
  OBJECT natAddrMapRowStatus
  SYNTAX RowStatus { active(1) }
  MIN-ACCESS   read-only
  DESCRIPTION
          "Write access is not required, and active is the only
           status that needs to be supported."
  OBJECT  natAddrBindGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natAddrBindGlobalAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natAddrPortBindGlobalAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natAddrPortBindGlobalAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPrivateAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPrivateSrcAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPrivateDstAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPublicAddrType
  SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPublicSrcAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
  OBJECT  natSessionPublicDstAddr
  SYNTAX  InetAddress (SIZE(4|16))
  DESCRIPTION
          "An implementation is required to support global IPv4
           and/or IPv6 addresses, depending on its support for
           IPv4 and IPv6."
::= { natMIBCompliances 2 }

END

Acknowledgements

The authors of the document would like to thank Randy Turner, Ashwini S.T., Kevin Luehrs, Sam Sankoorikal, and Juergen Quittek for their valuable feedback.

The authors would like to especially thank Juergen Schoenwaelder for his patient and fine-combed review and detailed comments as a MIB doctor. The NAT MIB is much clearer and flatter as a result of Juergen's suggestions.

Security Considerations

It is clear that this MIB can potentially be useful for configuration. Unauthorized access to the write-able objects could cause a denial of service and/or widespread network disturbance. Hence, the support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations.

At this writing, no security holes have been identified beyond those that SNMP Security is itself intended to address. These relate primarily to controlled access to sensitive information and the ability to configure a device - or which might result from operator error, which is beyond the scope of any security architecture.

There are a number of managed objects in this MIB that may contain information that may be sensitive from a business perspective, in that they may represent NAT bind and session information. The NAT bind and session objects reveal the identity of private hosts that are engaged in a session with external end nodes. A curious outsider

could monitor these two objects to assess the number of private hosts being supported by the NAT device. Further, a disgruntled former employee of an enterprise could use the NAT bind and session information to break into specific private hosts by intercepting the existing sessions or originating new sessions into the host. There are no objects that are sensitive in their own right, such as passwords or monetary amounts. It may even be important to control GET access to these objects and possibly to encrypt the values of these objects when they are sent over the network via SNMP. Not all versions of SNMP provide features for such a secure environment.

SNMP versions prior to SNMPv3 did not include adequate security. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB.

It is recommended that the implementers consider the security features as provided by the SNMPv3 framework (see RFC3410, section 8), including full support for the SNMPv3 cryptographic mechanisms (for authentication and privacy).

Further, deployment of SNMP versions prior to SNMPv3 is NOT RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to enable cryptographic security. It is then a customer/operator responsibility to ensure that the SNMP entity giving access to an instance of this MIB module is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them.

References

Normative References

RFC2578 McCloghrie, K., Perkins, D., and J. Schoenwaelder,

         "Structure of Management Information Version 2 (SMIv2)",
         STD 58, RFC 2578, April 1999.

RFC2579 McCloghrie, K., Perkins, D., and J. Schoenwaelder, "Textual

         Conventions for SMIv2", STD 58, RFC 2579, April 1999.

RFC2580 McCloghrie, K., Perkins, D., and J. Schoenwaelder,

         "Conformance Statements for SMIv2", STD 58, RFC 2580, April
         1999.

RFC3022 Srisuresh, P. and K. Egevang, "Traditional IP Network

         Address Translator (Traditional NAT)", RFC 3022, January
         2001.

RFC2663 Srisuresh, P. and M. Holdrege, "IP Network Address

         Translator (NAT) Terminology and Considerations", RFC 2663,
         August 1999.

RFC4001 Daniele, M., Haberman, B., Routhier, S., Schoenwaelder, J.,

         "Textual Conventions for Internet Network Addresses", RFC
         4001, February 2005.

RFC792 Postel, J., "Internet Control Message Protocol", STD 5, RFC

         792, September 1981.

RFC3489 Rosenberg, J., Weinberger, J., Huitema, C., and R. Mahy,

         "STUN - Simple Traversal of User Datagram Protocol (UDP)
         Through Network Address Translators (NATs)", RFC 3489,
         March 2003.

RFC2863 McCloghrie, K. and F. Kastenholz, "The Interfaces Group

         MIB", RFC 2863, June 2000.

RFC2463 Conta, A. and S. Deering, "Internet Control Message

         Protocol (ICMPv6) for the Internet Protocol Version 6
         (IPv6) Specification", RFC 2463, December 1998.

RFC3411 Harrington, D., Presuhn, R., and B. Wijnen, "An

         Architecture for Describing Simple Network Management
         Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
         December 2002.

RFC2119 Bradner, S., "Key words for use in RFCs to Indicate

         Requirement Levels", BCP 14, RFC 2119, March 1997.

RFC3413 Levi, D., Meyer, P., and B. Stewart, "Simple Network

         Management Protocol (SNMP) Applications", STD 62, RFC 3413,
         December 2002.

Informative References

RFC1918 Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,

         and E. Lear, "Address Allocation for Private Internets",
         BCP 5, RFC 1918, February 1996.

RFC3410 Case, J., Mundy, R., Partain, D., and B. Stewart,

         "Introduction and Applicability Statements for Internet-
         Standard Management Framework", RFC 3410, December 2002.

Authors' Addresses

R. Rohit Mascon Global Limited

  1. 59/2 100 ft Ring Road

Banashankari II Stage Bangalore 560 070 India

Phone: +91 80 679 6227 EMail: [email protected]

P. Srisuresh Caymas Systems, Inc. 1179-A North McDowell Blvd. Petaluma, CA 94954

Phone: (707) 283-5063 EMail: [email protected]

Rajiv Raghunarayan Cisco Systems Inc. 170 West Tasman Drive San Jose, CA 95134

Phone: +1 408 853 9612 EMail: [email protected]

Nalinaksh Pai Cisco Systems, Inc. Prestige Waterford No. 9, Brunton Road Bangalore - 560 025 India

Phone: +91 80 532 1300 extn. 6354 EMail: [email protected]

Cliff Wang Information Security Bank One Corp 1111 Polaris Pkwy Columbus, OH 43240

Phone: +1 614 213 6117 EMail: [email protected]

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