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    Monitoring BGP Neighbors

    Purpose

    Display information about BGP neighbors.

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

    Action

    To display information about BGP neighbors:

    • host1#show ip bgp neighbors
      BGP neighbor ID 10.2.1.48, remote AS 11488 (external peer)
        Remote router ID is 172.31.1.48, negotiated BGP version is 4
        Administrative status is Start, connection state is Established
        Reason for last reset was tcp connection error 
        TCP error code 60 (Connection timed out) 
        Connection has been established 1 time, up for 0 17:42:31
        Options:
          Default originate is disabled
          EBGP multi-hop is enabled
          IBGP single-hop is disabled
          Next hop self is disabled
          seconds
      Policy:
          Neighbor weight is 100
       Timers:
          Connect retry interval is 120 seconds
          Minimum route advertisement interval is 30 seconds
       Minimum AS origination interval is 10 seconds
          Configured keep-alive interval is 30 seconds, negotiated 30
             seconds
          Configured hold time is 90 seconds, negotiated 90
       TCP connection:
          Local IP address is 192.168.1.218, local port is 1024
          Remote IP address is 10.2.1.48, remote port is 179
       Statistics:
          Total of 4100 messages sent, 44913 messages received
          2053 update messages sent, 42785 update messages received
          0 00:00:17 since last update message was received
    • Fields relevant to multiprotocol extensions:
      Multi-protocol extensions negotiation:
          ip-v4 unicast: sent, received, used
          ip-v6 unicast-labeled: sent, received, used        
    • For the graceful restart capability, additional information is presented.
      • Fields concerning graceful restart attributes that apply to peers as a whole (for all address families):
        Graceful restart negotiation:
            Sent restart time is 120 seconds
            Sent restart state bit is zero (we are not restarting)
            Received restart time is 120 seconds
            Received restart state bit is zero (peer is not restarting)
            Maximum time for keeping stale paths is 360 seconds
      • Fields concerning attributes that apply to peers a particular address family:
        Peer is capable of preserving forwarding stat(3)
        Peer preserved forwarding state during last restart
        We have received an end-of-rib marker from the peer
        We have sent an end-of-rib marker to the peer
      • Fields relevant if the peer is currently restarting:
          Graceful restart waiting for the session to come back up
            Restart-time advertised by the peer is 120 seconds
            Remaining time for the peer to come back up is 117 seconds
            Remaining time for keeping stale routes from the peer is 357 seconds
      • Fields relevant during reconvergence after the peer has restarted:
          Graceful restart negotiation:
            Sent restart time is 120 seconds
            Sent restart state bit is zero (we are not restarting)
            Received restart time is 120 seconds
            Received restart state bit is zero (peer is not restarting)
            Maximum time for keeping stale paths is 300 seconds
            Remaining time for keeping stale routes from the peer is 297 seconds
    • For BFD, additional information is presented.
      • Fields relevant to BFD when BFD is not configured:
        BFD is disabled
      • Fields relevant to BFD when BFD is configured for an IBGP peer:
        BFD is enabled but not supported (IBGP neighbor)
      • Fields relevant to BFD when BFD is configured for a multihop EBGP peer:
        BFD is enabled but not supported (multi-hop EBGP neighbor)
      • Fields relevant to BFD when BFD is configured but the BGP session is not established:
        BFD is enabled:
             Single-hop IPv4 BFD session to 1.2.3.4
             Minimum transmit interval is 300 ms
             Minimum receive interval is 300 ms
             Multiplier is 3
             Waiting for BGP to become established before initiating BFD session
      • Fields relevant to BFD when BFD is configured, the BGP session is established, but the BFD protocol session is not up:
        BFD is enabled:
             Single-hop IPv4 BFD session to 1.2.3.4
             Minimum transmit interval is 300 ms
             Minimum receive interval is 300 ms
             Multiplier is 3
             BFD session is down
      • Fields relevant to BFD when BFD is configured, the BGP session is established, and the BFD protocol session is up:
        BFD is enabled:
             Single-hop IPv4 BFD session to 1.2.3.4
             Minimum transmit interval is 300 ms
             Minimum receive interval is 300 ms
             Multiplier is 3
             BFD session is up for 00:00:50
             Negotiated detection time is 900 ms
    • Fields relevant to conditional advertisement:
          Advertise-map is advertisetoR1 
              Condition-map: trigger1
              Sequence: 5
              Status: Withdraw
          Advertise-map is alternatetoR1
              Condition-map: trigger2
              Sequence: 10
              Status: Advertise

    Meaning

    Table 1 lists the show ip bgp neighbors command output fields.

    Table 1: show ip bgp neighbors Output Fields

    Field Name

    Field Description

    BGP neighbor ID

    BGP identifier of the BGP neighbor

    remote AS

    Remote AS of the BGP neighbor

    Description

    Textual description of the BGP neighbor

    Member of peer group

    Name of the peer group of which this BGP neighbor is a member

    Remote router ID

    Router ID of the remote router

    negotiated BGP version

    BGP version being used to communicate with the neighbor

    Administrative status

    Desired state of the peer connection

    Connection state

    Current state of the BGP connection

    Connection has been established

    Time that TCP connection was established

    Reason for last reset

    Reason for last reset of the BGP session

    TCP error code

    TCP connection error type

    Default originate

    Status of default originate (enabled or disabled)

    EBGP multi-hop

    Status of EBGP multihop (enabled or disabled)

    IBGP single-hop

    Status of IBGP single hop (enabled or disabled)

    Next hop self

    Status of next-hop self (enabled or disabled)

    Route reflector status

    Identifies the neighbor as a route-reflector client

    Neighbor weight

    Weight of routes from the BGP neighbor

    Incoming update distribute list

    Distribute list for incoming routes, if configured

    Outgoing update distribute list

    Distribute list for outgoing routes, if configured

    Incoming update filter list

    Update filter list for incoming routes, if configured

    Outgoing update filter list

    Update filter list for outgoing route, if configured

    Weight filter list

    Weight filter list for routes, if configured

    Incoming route map

    Incoming route map, if configured

    Outgoing route map

    Outgoing route map, if configured

    Connect retry interval

    Time between a BGP peer’s attempts to reestablish a connection to the neighbor

    Minimum route advertisement interval

    Minimum time between route advertisements

    Minimum AS origination interval

    Minimum time between advertisement of changes within the speaker’s AS

    Configured keep-alive interval

    Frequency of keep-alive messages generated

    Negotiated keepalive interval

    Negotiated frequency of keep-alive messages generated

    Configured hold time

    Configured maximum time allowed between received messages

    Negotiated hold time

    Negotiated maximum time allowed between received messages

    Configured update source IP address

    IP address used when sending update messages

    Local IP address

    Local IP address used for TCP communication to this peer

    Local port

    Local TCP port number used for TCP communication to this peer

    Remote IP address

    Remote IP address used for TCP communication to this peer

    Remote port

    Remote IP address used for TCP communication to this peer

    Total messages sent

    Total BGP messages sent to this neighbor

    Total messages received

    Total BGP messages received from this neighbor

    Total update messages sent

    Total BGP update messages sent to this neighbor

    Total update messages received

    Total BGP update messages received from this neighbor

    Time since last update message was received

    Time since last BGP update message was received from this neighbor

    Address Family dependent capabilities

    Lists type of ORF send and receive capability per address family and whether it is advertised (configured) or received

    Maximum number of ORF entries

    Limit of ORF entries that will be accepted from the neighbor

    Capability advertisement

    Lists whether the specific capability (capabilities option, deprecated dynamic capability negotiation, dynamic capability negotiation, multiprotocol extensions, route refresh, route refresh (Cisco proprietary), four octet AS numbers, and graceful restart) has been sent, received, or both

    Multi-protocol extensions negotiation

    Lists the relevant address family and whether it has been sent, received, or used

    BFD

    Status of BFD configuration, enabled, enabled but not supported because the peer is an IBGP neighbor a multihop EBGP neighbor, or disabled

    BFD session

    Type and address of peer to which BFD session is established

    Minimum transmit interval

    Desired interval between BFD packets transmitted to members of peer group

    Minimum receive interval

    Desired interval between BFD packets received from members of peer group

    Multiplier

    Number of BFD packets that can be missed before declaring BFD session down

    Negotiated detection time

    Interval between BFD packets negotiated by peers

    Advertise-map

    Name of route map that specifies routes to be advertised when routes in conditional route maps are matched

    Condition-map

    Name of route map that specifies routes to be matched by routes in the BGP routing table

    Sequence

    Position of the specified advertise route map in a list of advertise route maps configured for a particular peer within the same address-family. A lower sequence number has a higher priority; that route map is processed before one with a higher sequence number.

    Status

    Status of the routes specified by the route map, advertise (route map condition has been met) or withdraw (route map condition has not been met; regardless of this status, the specified routes might be governed by another route map with a lower sequence number and actually advertised or not according to that map

    Published: 2014-08-18