Advanced Configuration and Management Guide

 

 

Table 10.6: BGP4 Neighbor Information (Continued)

 

 

 

 

 

 

 

This Field...

 

Displays...

 

 

 

 

 

 

 

EBGP/IBGP

 

Whether the neighbor session is an IBGP session, an EBGP session,

 

 

 

 

or a confederation EBGP session.

 

 

 

 

• EBGP – The neighbor is in another AS.

 

 

 

 

• EBGP_Confed – The neighbor is a member of another sub-AS in

 

 

 

 

the same confederation.

 

 

 

 

• IBGP – The neighbor is in the same AS.

 

 

 

 

 

 

 

RouterID

 

The neighbor’s router ID.

 

 

 

 

 

 

 

PeerGroup

 

The name of the peer group the neighbor is in, if applicable.

 

 

 

 

 

 

 

State

 

The state of the router’s session with the neighbor. The states are

 

 

 

 

from this router’s perspective of the session, not the neighbor’s

 

 

 

 

perspective. The state values are based on the BGP4 state machine

 

 

 

 

values described in RFC 1771 and can be one of the following for

 

 

 

 

each router:

 

 

 

 

• IDLE – The BGP4 process is waiting to be started. Usually,

 

 

 

 

enabling BGP4 or establishing a neighbor session starts the

 

 

 

 

BGP4 process.

 

 

 

 

• A minus sign (-) indicates that the session has gone down

 

 

 

 

and the software is clearing or removing routes.

 

 

 

 

• ADMND – The neighbor has been administratively shut down.

 

 

 

 

See “Administratively Shutting Down a Session with a BGP4

 

 

 

 

Neighbor” on page 10-22.

 

 

 

 

• A minus sign (-) indicates that the session has gone down

 

 

 

 

and the software is clearing or removing routes.

 

 

 

 

• CONNECT – BGP4 is waiting for the connection process for the

 

 

 

 

TCP neighbor session to be completed.

 

 

 

 

• ACTIVE – BGP4 is waiting for a TCP connection from the

 

 

 

 

neighbor.

 

 

 

 

Note: If the state frequently changes between CONNECT and

 

 

 

 

ACTIVE, there may be a problem with the TCP connection.

 

 

 

 

• OPEN SENT – BGP4 is waiting for an Open message from the

 

 

 

 

neighbor.

 

 

 

 

• OPEN CONFIRM – BGP4 has received an OPEN message from

 

 

 

 

the neighbor and is now waiting for either a KEEPALIVE or

 

 

 

 

NOTIFICATION message. If the router receives a KEEPALIVE

 

 

 

 

message from the neighbor, the state changes to Established. If

 

 

 

 

the message is a NOTIFICATION, the state changes to Idle.

 

 

 

 

• ESTABLISHED – BGP4 is ready to exchange UPDATE

 

 

 

 

messages with the neighbor.

 

 

 

 

• If there is more BGP data in the TCP receiver queue, a plus

 

 

 

 

sign (+) is also displayed.

 

 

 

 

Note: If you display information for the neighbor using the

 

 

 

 

show ip bgp neighbor <ip-addr> command, the TCP receiver

 

 

 

 

queue value will be greater than 0.

 

 

 

 

 

 

 

 

 

 

 

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