White Papers

● 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
EMC 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<IP_address><OID>.
● An SNMP walk may terminate pre-maturely if the index does not increment lexicographically. Dell EMC 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.
● Multiple instances of the same NLRI in the BGP RIB are not supported and are set to zero in the SNMP query response.
● The f10BgpM2NlriIndex and f10BgpM2AdjRibsOutIndex fields are not used.
● Carrying MPLS labels in BGP is not supported. The f10BgpM2NlriOpaqueType and f10BgpM2NlriOpaquePointer fields are set
to zero.
● 4-byte ASN is supported. The f10BgpM2AsPath4byteEntry table contains 4-byte ASN-related parameters based on the
configuration.
● If a received update route matches with a local prefix, then that route is discarded. This behavior results from an incorrect
BGP configuration. To overcome this issue, you can trigger a route refresh after you properly configure BGP.
● If all the IP interfaces are in non-default VRFs, then you must have at least one interface in default VRF in order to configure
a routing process that works with non-default VRFs.
Traps (notifications) specified in the BGP4 MIB draft <draft-ietf-idr-bgp4–mibv2–05.txt> are not supported. Such
traps (bgpM2Established and bgpM2BackwardTransition) are supported as part of RFC 1657.
Configuration Information
The software supports BGPv4 as well as the following:
● deterministic multi-exit discriminator (MED) (default)
● a path with a missing MED is treated as worst path and assigned an MED value of (0xffffffff)
● the community format follows RFC 1998
● delayed configuration (the software at system boot reads the entire configuration file prior to sending messages to start
BGP peer sessions)
The following are not yet supported:
● auto-summarization (the default is no auto-summary)
● synchronization (the default is no synchronization)
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Border Gateway Protocol (BGP)