Network Working Group B. Haberman Request for Comments: 4292 Johns Hopkins University Obsoletes: 2096 April 2006 Category: Standards Track
IP Forwarding Table MIB
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 (2006).
Abstract
This document defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects related to the forwarding of Internet Protocol (IP) packets in an IP version- independent manner. This document obsoletes RFC 2096.
Table of Contents
1. Introduction ....................................................2 2. Conventions Used In This Document ...............................2 3. The Internet-Standard Management Framework ......................2 4. Overview ........................................................2 4.1. Relationship to Other MIBs .................................3 4.1.1.RFC 1213 ............................................3 4.1.2.RFC 1354 ............................................3 4.1.3.RFC 2096 ............................................3 4.1.4.RFC 2011 and 2465 ...................................3 5. Definitions .....................................................3 6. Security Considerations ........................................30 7. Changes from RFC 2096 ..........................................31 8. Normative References ...........................................32 9. Informative References .........................................32 10. Authors and Acknowledgements ..................................33
This document defines a portion of the Management Information Base (MIB) for use in managing objects related to the forwarding of Internet Protocol (IP) packets in an IP version-independent manner.
It should be noted that the MIB definition described herein does not support multiple instances based on the same address family type. However, it does support an instance of the MIB per address family.
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 RFC 2119 [RFC2119].
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].
The MIB consists of one current table and two current global objects.
1. The object inetCidrRouteNumber indicates the number of current routes. This is primarily to avoid having to read the table in order to determine this number.
2. The object inetCidrRouteDiscards counts the number of valid routes that were discarded from inetCidrRouteTable for any reason. This object replaces the ipRoutingDiscards and ipv6DiscardedRoutes objects.
3. The inetCidrRouteTable provides the ability to display IP version-independent multipath CIDR routes.
This MIB definition contains several deprecated and obsolete tables and objects. The following subsections describe the relationship between these objects and other MIB modules.
The ipForwardTable object replaced the ipRouteTable object from RFC 1213. It was in turn obsoleted by the ipCidrRouteTable defined in RFC 2096 [RFC2096].
In addition, RFC 1354 introduced ipForwardNumber. This object reflects the number of entries found in ipForwardTable. It was obsoleted by ipCidrRouteNumber, defined in RFC 2096.
In RFC 2096, the ipCidrRouteTable and ipCidrRouteNumber were introduced. The ipCidrRouteTable object supports multipath IP routes having the same network number but differing network masks. The number of entries in that table is reflected in ipCidrRouteNumber. These objects are deprecated by the definitions contained in this MIB definition.
RFC 2011 [RFC2011] contains the ipRoutingDiscards object, which counts the number of valid routes that have been removed from the ipCidrRouteTable object. The corresponding ipv6DiscardedRoutes object is defined in RFC 2465 [RFC2465]. These objects are deprecated in favor of the version-independent object inetCidrRouteDiscards defined in this MIB.
IMPORTS MODULE-IDENTITY, OBJECT-TYPE, IpAddress, Integer32, Gauge32, Counter32 FROM SNMPv2-SMI RowStatus FROM SNMPv2-TC
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MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF InterfaceIndexOrZero FROM IF-MIB ip FROM IP-MIB IANAipRouteProtocol FROM IANA-RTPROTO-MIB InetAddress, InetAddressType, InetAddressPrefixLength, InetAutonomousSystemNumber FROM INET-ADDRESS-MIB;
ipForward MODULE-IDENTITY LAST-UPDATED "200602010000Z" ORGANIZATION "IETF IPv6 Working Group http://www.ietf.org/html.charters/ipv6-charter.html" CONTACT-INFO "Editor: Brian Haberman Johns Hopkins University - Applied Physics Laboratory Mailstop 17-S442 11100 Johns Hopkins Road Laurel MD, 20723-6099 USA
Send comments to <ipv6@ietf.org>" DESCRIPTION "The MIB module for the management of CIDR multipath IP Routes.
Copyright (C) The Internet Society (2006). This version of this MIB module is a part of RFC 4292; see the RFC itself for full legal notices."
REVISION "200602010000Z" DESCRIPTION "IPv4/v6 version-independent revision. Minimal changes were made to the original RFC 2096 MIB to allow easy upgrade of existing IPv4 implementations to the version-independent MIB. These changes include:
Adding inetCidrRouteDiscards as a replacement for the deprecated ipRoutingDiscards and ipv6DiscardedRoutes objects.
Adding a new conformance statement to support the implementation of the IP Forwarding MIB in a read-only mode.
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The inetCidrRouteTable replaces the IPv4-specific ipCidrRouteTable, its related objects, and related conformance statements.
REVISION "199609190000Z" DESCRIPTION "Revised to support CIDR routes. Published as RFC 2096."
REVISION "199207022156Z" DESCRIPTION "Initial version, published as RFC 1354." ::= { ip 24 }
inetCidrRouteNumber OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of current inetCidrRouteTable entries that are not invalid." ::= { ipForward 6 }
inetCidrRouteDiscards OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of valid route entries discarded from the inetCidrRouteTable. Discarded route entries do not appear in the inetCidrRouteTable. One possible reason for discarding an entry would be to free-up buffer space for other route table entries." ::= { ipForward 8 }
-- Inet CIDR Route Table
-- The Inet CIDR Route Table deprecates and replaces the -- ipCidrRoute Table currently in the IP Forwarding Table MIB. -- It adds IP protocol independence.
inetCidrRouteTable OBJECT-TYPE SYNTAX SEQUENCE OF InetCidrRouteEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION
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"This entity's IP Routing table." REFERENCE "RFC 1213 Section 6.6, The IP Group" ::= { ipForward 7 }
inetCidrRouteEntry OBJECT-TYPE SYNTAX InetCidrRouteEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A particular route to a particular destination, under a particular policy (as reflected in the inetCidrRoutePolicy object).
Dynamically created rows will survive an agent reboot.
Implementers need to be aware that if the total number of elements (octets or sub-identifiers) in inetCidrRouteDest, inetCidrRoutePolicy, and inetCidrRouteNextHop exceeds 111, then OIDs of column instances in this table will have more than 128 sub- identifiers and cannot be accessed using SNMPv1, SNMPv2c, or SNMPv3." INDEX { inetCidrRouteDestType, inetCidrRouteDest, inetCidrRoutePfxLen, inetCidrRoutePolicy, inetCidrRouteNextHopType, inetCidrRouteNextHop } ::= { inetCidrRouteTable 1 }
inetCidrRouteDestType OBJECT-TYPE SYNTAX InetAddressType MAX-ACCESS not-accessible STATUS current DESCRIPTION "The type of the inetCidrRouteDest address, as defined in the InetAddress MIB.
Only those address types that may appear in an actual routing table are allowed as values of this object." REFERENCE "RFC 4001" ::= { inetCidrRouteEntry 1 }
inetCidrRouteDest OBJECT-TYPE SYNTAX InetAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The destination IP address of this route.
The type of this address is determined by the value of the inetCidrRouteDestType object.
The values for the index objects inetCidrRouteDest and inetCidrRoutePfxLen must be consistent. When the value of inetCidrRouteDest (excluding the zone index, if one is present) is x, then the bitwise logical-AND of x with the value of the mask formed from the corresponding index object inetCidrRoutePfxLen MUST be equal to x. If not, then the index pair is not consistent and an inconsistentName error must be returned on SET or CREATE requests."
::= { inetCidrRouteEntry 2 }
inetCidrRoutePfxLen OBJECT-TYPE SYNTAX InetAddressPrefixLength MAX-ACCESS not-accessible STATUS current DESCRIPTION "Indicates the number of leading one bits that form the mask to be logical-ANDed with the destination address before being compared to the value in the
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inetCidrRouteDest field.
The values for the index objects inetCidrRouteDest and inetCidrRoutePfxLen must be consistent. When the value of inetCidrRouteDest (excluding the zone index, if one is present) is x, then the bitwise logical-AND of x with the value of the mask formed from the corresponding index object inetCidrRoutePfxLen MUST be equal to x. If not, then the index pair is not consistent and an inconsistentName error must be returned on SET or CREATE requests."
::= { inetCidrRouteEntry 3 }
inetCidrRoutePolicy OBJECT-TYPE SYNTAX OBJECT IDENTIFIER MAX-ACCESS not-accessible STATUS current DESCRIPTION "This object is an opaque object without any defined semantics. Its purpose is to serve as an additional index that may delineate between multiple entries to the same destination. The value { 0 0 } shall be used as the default value for this object." ::= { inetCidrRouteEntry 4 }
inetCidrRouteNextHopType OBJECT-TYPE SYNTAX InetAddressType MAX-ACCESS not-accessible STATUS current DESCRIPTION "The type of the inetCidrRouteNextHop address, as defined in the InetAddress MIB.
Value should be set to unknown(0) for non-remote routes.
Only those address types that may appear in an actual routing table are allowed as values of this object." REFERENCE "RFC 4001" ::= { inetCidrRouteEntry 5 }
inetCidrRouteNextHop OBJECT-TYPE SYNTAX InetAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "On remote routes, the address of the next system en
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route. For non-remote routes, a zero length string.
The type of this address is determined by the value of the inetCidrRouteNextHopType object." ::= { inetCidrRouteEntry 6 }
inetCidrRouteIfIndex OBJECT-TYPE SYNTAX InterfaceIndexOrZero MAX-ACCESS read-create STATUS current DESCRIPTION "The ifIndex value that identifies the local interface through which the next hop of this route should be reached. A value of 0 is valid and represents the scenario where no interface is specified." ::= { inetCidrRouteEntry 7 }
inetCidrRouteType OBJECT-TYPE SYNTAX INTEGER { other (1), -- not specified by this MIB reject (2), -- route that discards traffic and -- returns ICMP notification local (3), -- local interface remote (4), -- remote destination blackhole(5) -- route that discards traffic -- silently } MAX-ACCESS read-create STATUS current DESCRIPTION "The type of route. Note that local(3) refers to a route for which the next hop is the final destination; remote(4) refers to a route for which the next hop is not the final destination.
Routes that do not result in traffic forwarding or rejection should not be displayed, even if the implementation keeps them stored internally.
reject(2) refers to a route that, if matched, discards the message as unreachable and returns a notification (e.g., ICMP error) to the message sender. This is used in some protocols as a means of correctly aggregating routes.
blackhole(5) refers to a route that, if matched, discards the message silently." ::= { inetCidrRouteEntry 8 }
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inetCidrRouteProto OBJECT-TYPE SYNTAX IANAipRouteProtocol MAX-ACCESS read-only STATUS current DESCRIPTION "The routing mechanism via which this route was learned. Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols." ::= { inetCidrRouteEntry 9 }
inetCidrRouteAge OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of 'too old' can be implied, except through knowledge of the routing protocol by which the route was learned." ::= { inetCidrRouteEntry 10 }
inetCidrRouteNextHopAS OBJECT-TYPE SYNTAX InetAutonomousSystemNumber MAX-ACCESS read-create STATUS current DESCRIPTION "The Autonomous System Number of the Next Hop. The semantics of this object are determined by the routing- protocol specified in the route's inetCidrRouteProto value. When this object is unknown or not relevant, its value should be set to zero." DEFVAL { 0 } ::= { inetCidrRouteEntry 11 }
inetCidrRouteMetric1 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS current DESCRIPTION "The primary routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's inetCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 }
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::= { inetCidrRouteEntry 12 }
inetCidrRouteMetric2 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS current DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's inetCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { inetCidrRouteEntry 13 }
inetCidrRouteMetric3 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS current DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's inetCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { inetCidrRouteEntry 14 }
inetCidrRouteMetric4 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS current DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's inetCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { inetCidrRouteEntry 15 }
inetCidrRouteMetric5 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS current DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing-
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protocol specified in the route's inetCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { inetCidrRouteEntry 16 }
inetCidrRouteStatus OBJECT-TYPE SYNTAX RowStatus MAX-ACCESS read-create STATUS current DESCRIPTION "The row status variable, used according to row installation and removal conventions.
A row entry cannot be modified when the status is marked as active(1)." ::= { inetCidrRouteEntry 17 }
ipForwardFullCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "When this MIB is implemented for read-create, the implementation can claim full compliance.
There are a number of INDEX objects that cannot be represented in the form of OBJECT clauses in SMIv2, but for which there are compliance requirements, expressed in OBJECT clause form in this description:
-- OBJECT inetCidrRouteDestType -- SYNTAX InetAddressType (ipv4(1), ipv6(2), -- ipv4z(3), ipv6z(4)) -- DESCRIPTION -- This MIB requires support for global and -- non-global ipv4 and ipv6 addresses.
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-- -- OBJECT inetCidrRouteDest -- SYNTAX InetAddress (SIZE (4 | 8 | 16 | 20)) -- DESCRIPTION -- This MIB requires support for global and -- non-global IPv4 and IPv6 addresses. -- -- OBJECT inetCidrRouteNextHopType -- SYNTAX InetAddressType (unknown(0), ipv4(1), -- ipv6(2), ipv4z(3) -- ipv6z(4)) -- DESCRIPTION -- This MIB requires support for global and -- non-global ipv4 and ipv6 addresses. -- -- OBJECT inetCidrRouteNextHop -- SYNTAX InetAddress (SIZE (0 | 4 | 8 | 16 | 20)) -- DESCRIPTION -- This MIB requires support for global and -- non-global IPv4 and IPv6 addresses. "
MODULE -- this module MANDATORY-GROUPS { inetForwardCidrRouteGroup }
OBJECT inetCidrRouteStatus SYNTAX RowStatus { active(1), notInService (2) } WRITE-SYNTAX RowStatus { active(1), notInService (2), createAndGo(4), destroy(6) } DESCRIPTION "Support for createAndWait is not required."
::= { ipForwardCompliances 3 }
ipForwardReadOnlyCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "When this MIB is implemented without support for read- create (i.e., in read-only mode), the implementation can claim read-only compliance." MODULE -- this module MANDATORY-GROUPS { inetForwardCidrRouteGroup }
OBJECT inetCidrRouteIfIndex MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteType
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MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteNextHopAS MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteMetric1 MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteMetric2 MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteMetric3 MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteMetric4 MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteMetric5 MIN-ACCESS read-only DESCRIPTION "Write access is not required."
OBJECT inetCidrRouteStatus SYNTAX RowStatus { active(1) } MIN-ACCESS read-only DESCRIPTION "Write access is not required."
inetCidrRouteNextHopAS, inetCidrRouteMetric1, inetCidrRouteMetric2, inetCidrRouteMetric3, inetCidrRouteMetric4, inetCidrRouteMetric5, inetCidrRouteStatus, inetCidrRouteNumber } STATUS current DESCRIPTION "The IP version-independent CIDR Route Table." ::= { ipForwardGroups 4 }
-- Deprecated Objects
ipCidrRouteNumber OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS deprecated DESCRIPTION "The number of current ipCidrRouteTable entries that are not invalid. This object is deprecated in favor of inetCidrRouteNumber and the inetCidrRouteTable." ::= { ipForward 3 }
-- IP CIDR Route Table
-- The IP CIDR Route Table obsoletes and replaces the ipRoute -- Table current in MIB-I and MIB-II and the IP Forwarding Table. -- It adds knowledge of the autonomous system of the next hop, -- multiple next hops, policy routing, and Classless -- Inter-Domain Routing.
ipCidrRouteTable OBJECT-TYPE SYNTAX SEQUENCE OF IpCidrRouteEntry MAX-ACCESS not-accessible STATUS deprecated DESCRIPTION "This entity's IP Routing table. This table has been deprecated in favor of the IP version neutral inetCidrRouteTable." REFERENCE "RFC 1213 Section 6.6, The IP Group" ::= { ipForward 4 }
ipCidrRouteEntry OBJECT-TYPE SYNTAX IpCidrRouteEntry MAX-ACCESS not-accessible STATUS deprecated DESCRIPTION "A particular route to a particular destination, under a
ipCidrRouteDest OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS deprecated DESCRIPTION "The destination IP address of this route.
This object may not take a Multicast (Class D) address value.
Any assignment (implicit or otherwise) of an instance of this object to a value x must be rejected if the bitwise logical-AND of x with the value of the corresponding instance of the ipCidrRouteMask object is not equal to x." ::= { ipCidrRouteEntry 1 }
STATUS deprecated DESCRIPTION "Indicate the mask to be logical-ANDed with the destination address before being compared to the value in the ipCidrRouteDest field. For those systems that do not support arbitrary subnet masks, an agent constructs the value of the ipCidrRouteMask by reference to the IP Address Class.
Any assignment (implicit or otherwise) of an instance of this object to a value x must be rejected if the bitwise logical-AND of x with the value of the corresponding instance of the ipCidrRouteDest object is not equal to ipCidrRouteDest." ::= { ipCidrRouteEntry 2 }
-- The following convention is included for specification -- of TOS Field contents. At this time, the Host Requirements -- and the Router Requirements documents disagree on the width -- of the TOS field. This mapping describes the Router -- Requirements mapping, and leaves room to widen the TOS field -- without impact to fielded systems.
ipCidrRouteTos OBJECT-TYPE SYNTAX Integer32 (0..2147483647) MAX-ACCESS read-only STATUS deprecated DESCRIPTION "The policy specifier is the IP TOS Field. The encoding of IP TOS is as specified by the following convention. Zero indicates the default path if no more specific policy applies.
+-----+-----+-----+-----+-----+-----+-----+-----+ | | | | | PRECEDENCE | TYPE OF SERVICE | 0 | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+
ipCidrRouteNextHop OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS deprecated DESCRIPTION "On remote routes, the address of the next system en route; Otherwise, 0.0.0.0." ::= { ipCidrRouteEntry 4 }
ipCidrRouteIfIndex OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "The ifIndex value that identifies the local interface through which the next hop of this route should be reached." DEFVAL { 0 } ::= { ipCidrRouteEntry 5 }
ipCidrRouteType OBJECT-TYPE SYNTAX INTEGER { other (1), -- not specified by this MIB reject (2), -- route that discards traffic local (3), -- local interface remote (4) -- remote destination } MAX-ACCESS read-create STATUS deprecated DESCRIPTION "The type of route. Note that local(3) refers to a route for which the next hop is the final destination; remote(4) refers to a route for which the next hop is not the final destination.
Routes that do not result in traffic forwarding or rejection should not be displayed, even if the implementation keeps them stored internally.
reject (2) refers to a route that, if matched, discards the message as unreachable. This is used in some protocols as a means of correctly aggregating routes." ::= { ipCidrRouteEntry 6 }
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ipCidrRouteProto OBJECT-TYPE SYNTAX INTEGER { other (1), -- not specified local (2), -- local interface netmgmt (3), -- static route icmp (4), -- result of ICMP Redirect
-- the following are all dynamic -- routing protocols egp (5), -- Exterior Gateway Protocol ggp (6), -- Gateway-Gateway Protocol hello (7), -- FuzzBall HelloSpeak rip (8), -- Berkeley RIP or RIP-II isIs (9), -- Dual IS-IS esIs (10), -- ISO 9542 ciscoIgrp (11), -- Cisco IGRP bbnSpfIgp (12), -- BBN SPF IGP ospf (13), -- Open Shortest Path First bgp (14), -- Border Gateway Protocol idpr (15), -- InterDomain Policy Routing ciscoEigrp (16) -- Cisco EIGRP } MAX-ACCESS read-only STATUS deprecated DESCRIPTION "The routing mechanism via which this route was learned. Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols." ::= { ipCidrRouteEntry 7 }
ipCidrRouteAge OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS deprecated DESCRIPTION "The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of `too old' can be implied, except through knowledge of the routing protocol by which the route was learned." DEFVAL { 0 } ::= { ipCidrRouteEntry 8 }
STATUS deprecated DESCRIPTION "A reference to MIB definitions specific to the particular routing protocol that is responsible for this route, as determined by the value specified in the route's ipCidrRouteProto value. If this information is not present, its value should be set to the OBJECT IDENTIFIER { 0 0 }, which is a syntactically valid object identifier, and any implementation conforming to ASN.1 and the Basic Encoding Rules must be able to generate and recognize this value." ::= { ipCidrRouteEntry 9 }
ipCidrRouteNextHopAS OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "The Autonomous System Number of the Next Hop. The semantics of this object are determined by the routing- protocol specified in the route's ipCidrRouteProto value. When this object is unknown or not relevant, its value should be set to zero." DEFVAL { 0 } ::= { ipCidrRouteEntry 10 }
ipCidrRouteMetric1 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "The primary routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipCidrRouteEntry 11 }
ipCidrRouteMetric2 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipCidrRouteProto value. If this metric is not used, its value should be
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set to -1." DEFVAL { -1 } ::= { ipCidrRouteEntry 12 }
ipCidrRouteMetric3 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipCidrRouteEntry 13 }
ipCidrRouteMetric4 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipCidrRouteEntry 14 }
ipCidrRouteMetric5 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS deprecated DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipCidrRouteProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipCidrRouteEntry 15 }
ipCidrRouteStatus OBJECT-TYPE SYNTAX RowStatus MAX-ACCESS read-create STATUS deprecated DESCRIPTION
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"The row status variable, used according to row installation and removal conventions." ::= { ipCidrRouteEntry 16 }
-- compliance statements
ipForwardCompliance MODULE-COMPLIANCE STATUS deprecated DESCRIPTION "The compliance statement for SNMPv2 entities that implement the ipForward MIB.
This compliance statement has been deprecated and replaced with ipForwardFullCompliance and ipForwardReadOnlyCompliance."
MODULE -- this module MANDATORY-GROUPS { ipForwardCidrRouteGroup }
This group has been deprecated and replaced with inetForwardCidrRouteGroup." ::= { ipForwardGroups 3 }
-- Obsoleted Definitions - Objects
ipForwardNumber OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS obsolete DESCRIPTION
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"The number of current ipForwardTable entries that are not invalid." ::= { ipForward 1 }
-- IP Forwarding Table
-- The IP Forwarding Table obsoletes and replaces the ipRoute -- Table current in MIB-I and MIB-II. It adds knowledge of -- the autonomous system of the next hop, multiple next hop -- support, and policy routing support.
ipForwardTable OBJECT-TYPE SYNTAX SEQUENCE OF IpForwardEntry MAX-ACCESS not-accessible STATUS obsolete DESCRIPTION "This entity's IP Routing table." REFERENCE "RFC 1213 Section 6.6, The IP Group" ::= { ipForward 2 }
ipForwardEntry OBJECT-TYPE SYNTAX IpForwardEntry MAX-ACCESS not-accessible STATUS obsolete DESCRIPTION "A particular route to a particular destination, under a particular policy." INDEX { ipForwardDest, ipForwardProto, ipForwardPolicy, ipForwardNextHop } ::= { ipForwardTable 1 }
ipForwardDest OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS obsolete DESCRIPTION "The destination IP address of this route. An entry with a value of 0.0.0.0 is considered a default route.
This object may not take a Multicast (Class D) address value.
Any assignment (implicit or otherwise) of an instance of this object to a value x must be rejected if the bitwise logical-AND of x with the value of the corresponding instance of the ipForwardMask object is not equal to x." ::= { ipForwardEntry 1 }
ipForwardMask OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-create STATUS obsolete DESCRIPTION "Indicate the mask to be logical-ANDed with the destination address before being compared to the value in the ipForwardDest field. For those systems that do not support arbitrary subnet masks, an agent constructs the value of the ipForwardMask by reference to the IP Address Class.
Any assignment (implicit or otherwise) of an instance of this object to a value x must be rejected if the bitwise logical-AND of x with the value of the corresponding instance of the ipForwardDest object is not equal to ipForwardDest." DEFVAL { '00000000'H } -- 0.0.0.0 ::= { ipForwardEntry 2 }
-- The following convention is included for specification -- of TOS Field contents. At this time, the Host Requirements -- and the Router Requirements documents disagree on the width -- of the TOS field. This mapping describes the Router
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-- Requirements mapping, and leaves room to widen the TOS field -- without impact to fielded systems.
ipForwardPolicy OBJECT-TYPE SYNTAX Integer32 (0..2147483647) MAX-ACCESS read-only STATUS obsolete DESCRIPTION "The general set of conditions that would cause the selection of one multipath route (set of next hops for a given destination) is referred to as 'policy'.
Unless the mechanism indicated by ipForwardProto specifies otherwise, the policy specifier is the IP TOS Field. The encoding of IP TOS is as specified by the following convention. Zero indicates the default path if no more specific policy applies.
+-----+-----+-----+-----+-----+-----+-----+-----+ | | | | | PRECEDENCE | TYPE OF SERVICE | 0 | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+
Protocols defining 'policy' otherwise must either define a set of values that are valid for this object or must implement an integer-instanced policy table for which this object's value acts as an index." ::= { ipForwardEntry 3 }
ipForwardNextHop OBJECT-TYPE
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SYNTAX IpAddress MAX-ACCESS read-only STATUS obsolete DESCRIPTION "On remote routes, the address of the next system en route; otherwise, 0.0.0.0." ::= { ipForwardEntry 4 }
ipForwardIfIndex OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "The ifIndex value that identifies the local interface through which the next hop of this route should be reached." DEFVAL { 0 } ::= { ipForwardEntry 5 }
ipForwardType OBJECT-TYPE SYNTAX INTEGER { other (1), -- not specified by this MIB invalid (2), -- logically deleted local (3), -- local interface remote (4) -- remote destination } MAX-ACCESS read-create STATUS obsolete DESCRIPTION "The type of route. Note that local(3) refers to a route for which the next hop is the final destination; remote(4) refers to a route for which the next hop is not the final destination.
Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipForwardTable object. That is, it effectively disassociates the destination identified with said entry from the route identified with said entry. It is an implementation-specific matter as to whether the agent removes an invalidated entry from the table. Accordingly, management stations must be prepared to receive tabular information from agents that corresponds to entries not currently in use. Proper interpretation of such entries requires examination of the relevant ipForwardType object." DEFVAL { invalid } ::= { ipForwardEntry 6 }
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ipForwardProto OBJECT-TYPE SYNTAX INTEGER { other (1), -- not specified local (2), -- local interface netmgmt (3), -- static route icmp (4), -- result of ICMP Redirect
-- the following are all dynamic -- routing protocols egp (5), -- Exterior Gateway Protocol ggp (6), -- Gateway-Gateway Protocol hello (7), -- FuzzBall HelloSpeak rip (8), -- Berkeley RIP or RIP-II is-is (9), -- Dual IS-IS es-is (10), -- ISO 9542 ciscoIgrp (11), -- Cisco IGRP bbnSpfIgp (12), -- BBN SPF IGP ospf (13), -- Open Shortest Path First bgp (14), -- Border Gateway Protocol idpr (15) -- InterDomain Policy Routing } MAX-ACCESS read-only STATUS obsolete DESCRIPTION "The routing mechanism via which this route was learned. Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols." ::= { ipForwardEntry 7 }
ipForwardAge OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-only STATUS obsolete DESCRIPTION "The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of `too old' can be implied except through knowledge of the routing protocol by which the route was learned." DEFVAL { 0 } ::= { ipForwardEntry 8 }
ipForwardInfo OBJECT-TYPE SYNTAX OBJECT IDENTIFIER MAX-ACCESS read-create STATUS obsolete
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DESCRIPTION "A reference to MIB definitions specific to the particular routing protocol that is responsible for this route, as determined by the value specified in the route's ipForwardProto value. If this information is not present, its value should be set to the OBJECT IDENTIFIER { 0 0 }, which is a syntactically valid object identifier, and any implementation conforming to ASN.1 and the Basic Encoding Rules must be able to generate and recognize this value." ::= { ipForwardEntry 9 }
ipForwardNextHopAS OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "The Autonomous System Number of the Next Hop. When this is unknown or not relevant to the protocol indicated by ipForwardProto, zero." DEFVAL { 0 } ::= { ipForwardEntry 10 }
ipForwardMetric1 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "The primary routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipForwardProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipForwardEntry 11 }
ipForwardMetric2 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipForwardProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipForwardEntry 12 }
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ipForwardMetric3 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipForwardProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipForwardEntry 13 }
ipForwardMetric4 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipForwardProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipForwardEntry 14 }
ipForwardMetric5 OBJECT-TYPE SYNTAX Integer32 MAX-ACCESS read-create STATUS obsolete DESCRIPTION "An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipForwardProto value. If this metric is not used, its value should be set to -1." DEFVAL { -1 } ::= { ipForwardEntry 15 }
-- Obsoleted Definitions - Groups -- compliance statements
ipForwardOldCompliance MODULE-COMPLIANCE STATUS obsolete DESCRIPTION "The compliance statement for SNMP entities that implement the ipForward MIB."
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MODULE -- this module MANDATORY-GROUPS { ipForwardMultiPathGroup }
There are a number of management objects defined in this MIB module with a MAX-ACCESS clause of read-write and/or read-create. Such objects may be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. These are the tables and objects and their sensitivity/vulnerability:
1. The inetCidrRouteTable contains routing and forwarding information that is critical to the operation of the network node (especially routers). Allowing unauthenticated write access to this table can compromise the validity of the forwarding information.
Some of the readable objects in this MIB module (i.e., objects with a MAX-ACCESS other than not-accessible) may be considered sensitive or vulnerable in some network environments. It is thus important to control even GET and/or NOTIFY access to these objects and possibly to even encrypt the values of these objects when sending them over the network via SNMP. These are the tables and objects and their sensitivity/vulnerability:
1. The inetCidrRouteTable contains routing and forwarding information that can be used to compromise a network.
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Specifically, this table can be used to construct a map of the network in preparation for a denial-of-service attack on the network infrastructure.
2. The inetCidrRouteProto object identifies the routing protocols in use within a network. This information can be used to determine how a denial-of-service attack should be launched.
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 module.
It is RECOMMENDED that 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.
This document obsoletes RFC 2096 in the following ways:
1. Replaces ipCidrRouteTable with inetCidrRouteTable. This applies to corresponding objects and conformance statements.
2. Utilizes the InetAddress TC to support IP version-independent implementations of the forwarding MIB. This gives common forwarding MIB support for IPv4 and IPv6.
3. Creates a read-only conformance statement to support implementations that only wish to retrieve data.
4. Creates the inetCidrRouteDiscards object to replace the deprecated ipRoutingDiscards and ipv6DiscardedRoutes objects.
The inetCidrRouteTable retains the logical structure of the ipCidrRouteTable in order to allow the easy upgrade of existing IPv4 implementations to the version-independent MIB.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[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.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000.
[RFC4001] Daniele, M., Haberman, B., Routhier, S., and J. Schoenwaelder, "Textual Conventions for Internet Network Addresses", RFC 4001, February 2005.
[RFC4293] Routhier, S., Ed., "Management Information Base for the Internet Protocol (IP), RFC 4293, April 2006.
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction and Applicability Statements for Internet- Standard Management Framework", RFC 3410, December 2002.
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[RFC2465] Haskin, D. and S. Onishi, Management Information Base for IP Version 6: Textual Conventions and General Group", RFC 2465, December 1998.
The following people provided text for this version of the document, or were authors of previous versions:
Fred Baker, Cisco Bill Fenner, AT&T Research Brian Haberman, Johns Hopkins University - Applied Physics Laboratory Juergen Schoenwalder, TU Braunschweig Dave Thaler, Microsoft Margaret Wasserman, Thingmagic
Dario Accornero, Mark Adam, Qing Li, and Shawn Routhier reviewed the document and provided helpful feedback.
Mike Heard provided valuable feedback as the MIB Doctor for this document.
Editors' Contact Information
Comments or questions regarding this document should be sent to:
Brian Haberman Johns Hopkins University - Applied Physics Laboratory Mailstop 17-S442 11100 Johns Hopkins Road Laurel MD, 20723-6099 USA
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