Usage
Information
In BGP, route attributes are maintained at different locations. When attributes that
correspond to multiple routes change, then attribute counts that the
show ip
bgp summary
command displays are calculated as summations of attributes
corresponding to all the associated routes. For example, if cluster_id is an attribute
associated with thousand routes that contain exactly the same set of attributes,
then the cluster_id count is 1. If these thousand routes are set with different
attribute values with the same cluster_id, then the cluster_id count is 1000, since
the same value is stored for thousand different attribute records.
The attribute next-hop is a part of the BGP attribute data structure.
If two peers send the same route that contains similar path attributes, then two
entries are maintained in the back-end, as both these entries have different next-
hops. If this same route is sent to a different peer, an entry for each peer is created,
as the next-hop is different. As a result, the BGP attributes count in the summary
output will differ accordingly.
The following describes the
show ip bgp summary
command shown in the
following example.
Field
Description
BGP router
identifier
Displays the local router ID and the AS number.
BGP table version
Displays the BGP table version and the main routing table
version.
network entries
Displays the number of network entries, route paths, and
the amount of memory used to process those entries.
paths
Displays the number of paths and the amount of memory
used.
denied paths
Displays the number of denied paths and the amount of
memory used.
BGP path attribute
entries
Displays the number of BGP path attributes and the amount
of memory used to process them.
BGP AS-PATH
entries
Displays the number of BGP AS_PATH attributes processed
and the amount of memory used to process them.
BGP community
entries
Displays the number of BGP COMMUNITY attributes
processed and the amount of memory used to process
them. The
show ip bgp community
command provides
more details on the COMMUNITY attributes.
Dampening
enabled
Displayed only when you enable dampening. Displays the
number of paths designated as history, dampened, or
penalized.
Neighbor
Displays the BGP neighbor address.
AS
Displays the AS number of the neighbor.
Border Gateway Protocol
483
