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 35 lists the show ip bgp neighbors command output fields.

Table 35: 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

Monitoring BGP Neighbors

Purpose

Action

Meaning

Related Documentation