Administrator Guide

Version Description
9.9(0.0) Introduced on the C9010.
9.8(0.0) Introduced on the S3048–ON and S4048–ON.
9.7(0.0) Added the ipv4 multicast and ipv6 unicast parameters.
9.4(0.0) Added support for VRF.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
7.8.1.0 Introduced on the S-Series.
7.7.1.0 Introduced on the C-Series.
Usage Information
To determine a BGP session flap, both a route-down event and a subsequent route-up event corresponding to a
single route are considered. As a result, a flap event is penalized only one time during the route-down event. The
subsequent route-up event corresponding to the same route is not considered as a flap and is not penalized.
The history paths that the show ip bgp command displays contain only the prefix and the next-hop
information. The next-hop information shows the ip address of the neighbor. It does not show the actual next-hop
details.
The following describes the show ip bgp damp command shown in the following example.
Field Description
Network Displays the network ID to which the route is dampened.
From Displays the IP address of the neighbor advertising the dampened route.
Reuse Displays the hour:minutes:seconds until the dampened route is available.
Path Lists all the ASs the dampened route passed through to reach the destination network.
Example
Dell#show ip bgp dampened-paths
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
BGP local router ID is 192.168.11.5
Status codes: s suppressed, S stale, d dampened, h history, * valid, > best
Path source: I - internal, a - aggregate, c - confed-external, r -
redistributed
n - network, D - denied, S - stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network From Reuse Path
d 55.0.0.0/24 172.16.0.2 00:36:23 200
Dell#
BGP Extended Communities (RFC 4360)
BGP Extended Communities, as defined in RFC 4360, is an optional transitive BGP attribute.
BGP Extended Communities provides two major advantages over Standard Communities:
• The range is extended from 4-octet (AA:NN) to 8-octet (Type:Value) to provide enough number communities.
• Communities are structured using a new “Type” field (1 or 2-octets), allowing you to provide granular control/filter routing information
based on the type of extended communities.
412
Border Gateway Protocol