Juniper Networks J-Series manual Down to Up, BGP Neighbors

J-series™ Services Router Administration Guide

Table 53: Summary of Key BGP Routing Output Fields (continued)

Field	Values	Additional Information
Down	Number of unavailable BGP peers.
Peers
Peer	Address of each BGP peer.
InPkt	Number of packets received from the peer,
OutPkt	Number of packets sent to the peer.
Flaps	Number of times a BGP session has changed state from	A high number of flaps might indicate a problem with
	Down to Up.	the interface on which the BGP session is enabled.
Last	Last time that a session became available or	If the BGP session is unavailable, this time might be
Up/Down	unavailable, since the neighbor transitioned to or from	useful in determining when the problem occurred.
	the established state.
State	A multipurpose field that displays information about
	BGP peer sessions. The contents of this field depend
	upon whether a session is established.
	■ If a peer is not established, the field shows the
	state of the peer session: Active, Connect, or Idle.
	■ If a BGP session is established, the field shows the
	number of active, received, and damped routes
	that are received from a neighbor. For example,
	2/4/0 indicates two active routes, four received
	routes, and no damped routes.

BGP Neighbors

Peer	Address of the BGP neighbor.
AS	AS number of the peer.
Type	Type of peer: Internal or External.
State	Current state of the BGP session:
	■ Active—BGP is initiating a TCP connection in an
	attempt to connect to a peer. If the connection is
	successful, BGP sends an open message.
	■ Connect—BGP is waiting for the TCP connection
	to become complete.
	■ Established—The BGP session has been
	established, and the peers are exchanging BGP
	update messages.
	■ Idle—This is the first stage of a connection. BGP
	is waiting for a Start event.
	■ OpenConfirm—BGP has acknowledged receipt of
	an open message from the peer and is waiting to
	receive a keepalive or notification message.
	■ OpenSent—BGP has sent an open message and is
	waiting to receive an open message from the peer.

Generally, the most common states are Active, which indicates a problem establishing the BGP conenction, and Established, which indicates a successful session setup. The other states are transition states, and BGP sessions normally do not stay in those states for extended periods of time.

118■ Using the Monitoring Tools