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Usage
Information
After a peer reset, the contents of the notification log messages is displayed in hex values for debugging.
The neighbor information that this command displays does not include counts corresponding to
ignored prefixes and updates. However, the martian case is an exception where neighbor information
corresponding to ignored updates is displayed.
BGP shows the exact information that is exchanged between the BGP peers. It also indicates whether or
not this information is received by the BGP peer.
The following describes the show ip bgp neighbors command shown in the following examples.
The Lines
Beginning
with:
Description
BGP neighbor Displays the BGP neighbor address and its AS number. The last phrase in the line
indicates whether the link between the BGP router and its neighbor is an external
or internal one. If they are located in the same AS, the link is internal; otherwise the
link is external.
BGP version Displays the BGP version (always version 4) and the remote router ID.
BGP state Displays the neighbor’s BGP state and the amount of time in
hours:minutes:seconds it has been in that state.
Last read This line displays the following information:
● last read is the time (hours:minutes:seconds) the router read a message from
its neighbor
● hold time is the number of seconds configured between messages from its
neighbor
● keepalive interval is the number of seconds between keepalive messages to help
ensure that the TCP session is still alive.
Received
messages
This line displays the number of BGP messages received, the number of
notifications (error messages), and the number of messages waiting in a queue
for processing.
Sent messages The line displays the number of BGP messages sent, the number of notifications
(error messages), and the number of messages waiting in a queue for processing.
Received updates This line displays the number of BGP updates received and sent.
Soft
reconfiguration
This line indicates that soft reconfiguration inbound is configured.
Minimum time Displays the minimum time, in seconds, between advertisements.
(list of inbound
and outbound
policies)
Displays the policy commands configured and the names of the Route map, AS-
PATH ACL, or Prefix list configured for the policy.
For address
family:
Displays the IPv4 Unicast as the address family.
BGP table
version
Displays which version of the primary BGP routing table the router and the
neighbor are using.
accepted
prefixes
Displays the number of network prefixes the router accepts and the amount of
memory used to process those prefixes.
Prefix advertised Displays the number of network prefixes advertised, the number rejected, and the
number withdrawn from the BGP routing table.
Connections
established
Displays the number of TCP connections established and dropped between the two
peers to exchange BGP information.
Last reset Displays the amount of time since the peering session was last reset. Also states
if the peer resets the peering session. If the peering session was never reset, the
word never is displayed.
Local host: Displays the peering address of the local router and the TCP port number.
430 Border Gateway Protocol