The Management Information Base (MIB) that supports BGP is the CISCO-BGP4-MIB. The BGP MIB Support Enhancements feature introduces
support in the CISCO-BGP4-MIB for new SNMP notifications. The following sections describe the objects and notifications (traps)
that are supported:
BGP FSM Transition Change Support
The cbgpRouteTable supports BGP Finite State Machine (FSM) transition state changes.
The cbgpFsmStateChange object allows you to configure SNMP notifications (traps) for all FSM transition state changes. This
notification contains the following MIB objects:
-
bgpPeerLastError
-
bgpPeerState
-
cbgpPeerLastErrorTxt
-
cbgpPeerPrevState
The cbgpBackwardTransition object supports all BGP FSM transition state changes. This object is sent each time the FSM moves
to either a higher or lower numbered state. This notification contains the following MIB objects:
-
bgpPeerLastError
-
bgpPeerState
-
cbgpPeerLastErrorTxt
-
cbgpPeerPrevState
The
snmp-server
enable
bgp
traps command allows you to enable the traps individually or together with the existing FSM backward transition and established
state traps as defined in
RFC 1657.
BGP Route Received Route Support
The cbgpRouteTable object supports the total number of routes received by a BGP neighbor. The following MIB object is used
to query the CISCO-BGP4-MIB for routes that are learned from individual BGP peers:
Routes are indexed by the address-family identifier (AFI) or subaddress-family identifier (SAFI). The prefix information
displayed in this table can also viewed in the output of the
show
ip
bgp command.
BGP Prefix Threshold Notification Support
The cbgpPrefixMaxThresholdExceed and cbgpPrfefixMaxThresholdClear objects were introduced to allow you to poll for the total
number of routes received by a BGP peer.
The cbgpPrefixMaxThresholdExceed object allows you to configure SNMP notifications to be sent when the prefix count for a
BGP session has exceeded the configured value. This notification is configured on a per address family basis. The prefix threshold
is configured with the
neighbor
maximum-prefix command. This notification contains the following MIB objects:
-
cbgpPeerPrefixAdminLimit
-
cbgpPeerPrefixThreshold
The cbgpPrfefixMaxThresholdClear object allows you to configure SNMP notifications to be sent when the prefix count drops
below the clear trap limit. This notification is configured on a per address family basis. This notification contains the
following objects:
Notifications are sent when the prefix count drops below the clear trap limit for an address family under a BGP session after
the cbgpPrefixMaxThresholdExceed notification is generated. The clear trap limit is calculated by subtracting 5 percent from
the maximum prefix limit value configured with the
neighbor
maximum-prefix command. This notification will not be generated if the session goes down for any other reason after the cbgpPrefixMaxThresholdExceed
is generated.
VPNv4 Unicast Address Family Route Support
The cbgpRouteTable object allows you to configure SNMP GET operations for VPNv4 unicast address-family routes.
The following MIB object allows you to query for multiple BGP capabilities (for example, route refresh, multiprotocol BGP
extensions, and graceful restart):
The following MIB object allows you to query for IPv4 and VPNv4 address family routes:
Each route is indexed by peer address, prefix, and prefix length. This object indexes BGP routes by the AFI and then by the
SAFI. The AFI table is the primary index, and the SAFI table is the secondary index. Each BGP speaker maintains a local Routing
Information Base (RIB) for each supported AFI and SAFI combination.
cbgpPeerTable Support
The cbgpPeerTable has been modified to support the enhancements described in this document. The following new table objects
are supported in the CISCO-BGP-MIB.my:
-
cbgpPeerLastErrorTxt
-
cbgpPeerPrevState
The following table objects are not supported. The status of these objects is listed as deprecated, and these objects are
not operational:
-
cbgpPeerPrefixAccepted
-
cbgpPeerPrefixDenied
-
cbgpPeerPrefixLimit
-
cbgpPeerPrefixAdvertised
-
cbgpPeerPrefixSuppressed
-
cbgpPeerPrefixWithdrawn