Monitoring BGP Routes in a Community

Purpose

Display all routes that are members of the specified BGP community. Report whether the indirect next hop of a route is unreachable; if not, display the IGP cost to the indirect next hop. Does not accept regular expressions.

The show ip bgp community and show bgp ipv6 community commands display similar information.

Action

To display all routes that are members of the specified BGP community:

Specify the community number in AA:NN format:

AA—Number that identifies the autonomous system
NN—Number that identifies the community within the autonomous system

host1#show ip bgp community 999:999

Local router ID 192.168.1.153, local AS 100
  40845 paths, 40845 distinct prefixes (2940840 bytes used)
  40845 paths selected for route table installation
  13651 path attribute entries (1864908 bytes used)

  Prefix        Peer       Next-hop        MED CalPrf Weight Origin
> 24.0.0.0/12   10.5.0.48  10.5.0.48            100    100    IGP
> 24.4.252.0/22 10.5.0.48  10.5.0.48            100    100    IGP
> 24.6.0.0/23   10.5.0.48  10.5.0.48            100    100    IGP
> 24.6.11.0/24  10.5.0.48  10.5.0.48            100    100    IGP

Meaning

Table 29 lists the show ip bgp community command output fields.

Table 29: show ip bgp community Output Fields

Field Name	Field Description
Local router ID	BGP router ID of the local router
local AS	Local autonomous system number
routes	Total number of routes stored in the BGP routing table and amount of memory consumed by routes. If several peers have advertised a route to the same prefix, all routes are included in this count.
paths	Total number of routes stored in the BGP routing table. If several peers have advertised a route to the same prefix, all routes are included in this count.
distinct prefixes	Number of routes to unique prefixes stored in the BGP routing table. If several peers have advertised a route to the same prefix, only the best route is included in this count.
routes selected for route table installation	Number of routes in the BGP routing table that have been inserted into the IP routing table
path attribute entries	Number of distinct path attributes stored in BGP's internal path attributes table. If BGP receives two routes for different prefixes but with identical path attributes, BGP will create only one entry in its internal path attribute table and share it between the two routes to conserve memory.
Prefix	Prefix for the routing table entry
Peer	IP address of BGP peer
Next hop IP address	IP address of the next hop
MED	Multiexit discriminator for the route
CalPrf	Calculated preference for the route
Weight	Assigned path weight
Origin	Origin of the route

Monitoring BGP Routes in a Community

Purpose

Action

Meaning

Related Documentation