RIP Version 2 MIB Extension
obsoletes
- rfc-1389 — RIP Version 2 MIB Extensions
Extracted elements (23)
Demand RIP send modes (ripV1Demand and ripV2Demand) were added to rip2IfConfSend rather than creating a separate Demand RIP MIB, intentionally avoiding the need for an additional MIB module to manage WAN interface behavior.
Unnumbered interfaces are supported by using a pseudo-address in the class A 0.0.0.0 network, where the least significant 24 bits encode the ifIndex of the relevant IP interface. This allows the existing IpAddress-indexed tables to accommodate unnumbered interfaces without a schema change, and is backward compatible with RFC 1389.
rip1Compatible send mode broadcasts RIP-2 updates using RFC 1058 route subsumption rules, allowing RIP-2 routers to interoperate with RIP-1 neighbors that cannot process multicast packets. ripVersion2 mode uses multicast and is not backward compatible with RIP-1 receivers.
The rip2IfConfDomain object is marked obsolete because Route Domains are deprecated in the current version of the RIP-2 protocol. rip2PeerDomain cannot be deprecated (as an index object) but must always carry the value zero.
Implementation of the rip2GlobalGroup, rip2IfStatGroup, and rip2IfConfGroup is mandatory for systems implementing RIP-2. The rip2PeerGroup is optional.
On a numbered interface, rip2IfConfSrcAddress MUST be the same value as rip2IfConfAddress. On an unnumbered interface, it must be the value of rip2IfConfAddress for some interface on the system.
rip2PeerDomain must always be zero because Routing Domain support is deprecated. Despite being an index object (which cannot be formally deprecated), its value is constrained to zero.
rip2GlobalQueries is a read-only Counter32 (OID rip2Globals 2) counting the number of responses sent to RIP queries from other systems. Implementation is mandatory for systems implementing RIP-2.
rip2GlobalRouteChanges is a read-only Counter32 (OID rip2Globals 1) counting the number of route changes made to the IP Route Database by RIP, excluding route age refreshes. Implementation is mandatory for systems implementing RIP-2.
rip2IfConfAuthKey is a read-create OCTET STRING of size 0..16 holding the authentication key. Strings shorter than 16 octets are left-justified and right-padded with null bytes. Reading this object always returns a zero-length string to prevent authentication bypass.
rip2IfConfAuthType is a read-create INTEGER with values noAuthentication(1), simplePassword(2), and md5(3), defaulting to noAuthentication. It controls the authentication mechanism applied to RIP packets on the interface.
rip2IfConfDefaultMetric is a read-create INTEGER (0..15) specifying the metric for the default route entry in RIP updates on the interface. A value of zero means no default route is originated; another router's default may still be propagated.
rip2IfConfReceive is a read-create INTEGER controlling which RIP version updates are accepted: rip1(1), rip2(2), rip1OrRip2(3), doNotRecieve(4). Values rip2 and rip1OrRip2 imply reception of multicast packets. Default is rip1OrRip2.
rip2IfConfSend is a read-create INTEGER controlling what the router sends on the interface: doNotSend(1), ripVersion1(2), rip1Compatible(3) (broadcast RIP-2 with RFC 1058 subsumption), ripVersion2(4) (multicast RIP-2), ripV1Demand(5), ripV2Demand(6). Default is rip1Compatible.
rip2IfConfSrcAddress is a read-create IpAddress added to support unnumbered interfaces, specifying the source address used for RIP packets sent on the interface. On numbered interfaces it must equal rip2IfConfAddress; on unnumbered interfaces it must be rip2IfConfAddress of some interface on the system.
rip2IfConfTable (OID rip2 3) is a mandatory interface configuration table indexed by rip2IfConfAddress, containing authentication type and key, send/receive mode, default metric, row status, and source address for unnumbered interfaces.
rip2IfStatAddress is a read-only IpAddress index for rip2IfStatTable. For unnumbered interfaces, it uses the pseudo-address 0.0.0.N where N (least significant 24 bits) is the ifIndex of the relevant IP interface in network byte order.
rip2IfStatTable (OID rip2 2) is a mandatory interface status table indexed by rip2IfStatAddress, containing per-interface counters: rip2IfStatRcvBadPackets (discarded RIP responses), rip2IfStatRcvBadRoutes (ignored routes in valid packets), rip2IfStatSentUpdates (triggered updates sent), and rip2IfStatStatus (RowStatus for row deletion).
rip2PeerEntry contains rip2PeerAddress (source IP), rip2PeerDomain (must be zero), rip2PeerLastUpdate (sysUpTime of most recent update), rip2PeerVersion (RIP version from last packet header, INTEGER 0..255), rip2PeerRcvBadPackets, and rip2PeerRcvBadRoutes.
rip2PeerTable (OID rip2 4) is an optional table indexed by rip2PeerAddress and rip2PeerDomain, tracking active RIP peers—routers from which a valid RIP update was heard within the last 180 seconds—to assist in debugging neighbor relationships.
RouteTag is a textual convention defined as OCTET STRING (SIZE 2) representing the contents of the Route Domain field in RIP packet headers or route entries. Its use is deprecated along with the Route Domain concept itself.
Reading rip2IfConfAuthKey always returns an OCTET STRING of length zero, preventing authentication keys from being retrieved via SNMP and thus preventing authentication bypass through MIB access. The security considerations section otherwise states that security issues are not discussed in this memo.
rip2IfConfAuthKey is encoded as an OCTET STRING of 0 to 16 octets. If fewer than 16 octets are supplied, the key is left-justified and right-padded with null bytes (0x00) to fill 16 octets on the wire.