Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 178

BGP4 Management Information Base (MIB) The FORCE10-BGP4-V2-MIB enhances support for the BGP management information base (MIB) with many new simple network management protocol (SNMP) objects and notifications (traps) defined in draft-ietf-idr-bgp4-mibv2-05. To see these enhancements, download the MIB from the Dell website. NOTE: For the Force10-BGP4-V2-MIB and other MIB documentation, refer to the Dell iSupport web page. Important Points to Remember • Because eBGP packets are not controlled by the ACL, packets from BGP neighbors cannot be blocked using the deny ip command. • The f10BgpM2AsPathTableEntry table, f10BgpM2AsPathSegmentIndex, and f10BgpM2AsPathElementIndex are used to retrieve a particular ASN from the AS path. These indices are assigned to the AS segments and individual ASN in each segment starting from 0. For example, an AS path list of {200 300 400} 500 consists of two segments: {200 300 400} with segment index 0 and 500 with segment index 1. ASN 200, 300, and 400 are assigned 0, 1, and 2 element indices in that order. • Unknown optional transitive attributes within a given path attribute (PA) are assigned indices in order. These indices correspond to the f10BgpM2PathAttrUnknownIndex field in the f10BgpM2PathAttrUnknownEntry table. • Negotiation of multiple instances of the same capability is not supported. F10BgpM2PeerCapAnnouncedIndex and f10BgpM2PeerCapReceivedIndex are ignored in the peer capability lookup. • Configure inbound BGP soft-reconfiguration on a peer for f10BgpM2PrefixInPrefixesRejected to display the number of prefixes filtered due to a policy. If you do enable BGP soft-reconfig, the denied prefixes are not accounted for. • F10BgpM2AdjRibsOutRoute stores the pointer to the NLRI in the peer's Adj-Rib-Out. • PA Index (f10BgpM2PathAttrIndex field in various tables) is used to retrieve specific attributes from the PA table. The Next- Hop, RR Cluster-list, and Originator ID attributes are not stored in the PA Table and cannot be retrieved using the index passed in command. These fields are not populated in f10BgpM2PathAttrEntry, f10BgpM2PathAttrClusterEntry, and f10BgpM2PathAttrOriginatorIdEntry. • F10BgpM2PathAttrUnknownEntry contains the optional-transitive attribute details. • Query for f10BgpM2LinkLocalNextHopEntry returns the default value for Link-local Next-hop. • RFC 2545 and the f10BgpM2Rfc2545Group are not supported. • An SNMP query displays up to 89 AS paths. A query for a larger AS path count displays as "..." at the end of the output. • SNMP set for BGP is not supported. For all peer configuration tables (f10BgpM2PeerConfigurationGroup, f10BgpM2PeerRouteReflectorCfgGroup, and f10BgpM2PeerAsConfederationCfgGroup), an SNMP set operation returns an error. Only SNMP queries are supported. In addition, the f10BgpM2CfgPeerError, f10BgpM2CfgPeerBgpPeerEntry, and f10BgpM2CfgPeerRowEntryStatus fields are to hold the SNMP set status and are ignored in SNMP query. • The AFI/SAFI is not used as an index to the f10BgpM2PeerCountersEntry table. The BGP peer's AFI/ SAFI (IPv4 Unicast or IPv6 Multicast) is used for various outbound counters. Counters corresponding to IPv4 Multicast cannot be queried. • The f10BgpM2[Cfg]PeerReflectorClient field is populated based on the assumption that route-reflector clients are not in a full mesh if you enable BGP client-2-client reflection and that the BGP speaker acting as reflector advertises routes learned from one client to another client. If disabled, it is assumed that clients are in a full mesh and there is no need to advertise prefixes to the other clients. • High CPU utilization may be observed during an SNMP walk of a large BGP Loc-RIB. • To avoid SNMP timeouts with a large-scale configuration (large number of BGP neighbors and a large BGP Loc-RIB), Dell Networking recommends setting the timeout and retry count values to a relatively higher number. For example, t = 60 or r = 5. • To return all values on an snmpwalk for the f10BgpM2Peer sub-OID, use the -C c option, such as snmpwalk -v 2c -C c -c public. • An SNMP walk may terminate pre-maturely if the index does not increment lexicographically. Dell Networking recommends using options to ignore such errors. • Multiple BPG process instances are not supported. Thus, the f10BgpM2PeerInstance field in various tables is not used to locate a peer. Border Gateway Protocol IPv4 (BGPv4) 178