Neighbor configuration and neighbor policy configuration

Table 37: Neighbor configuration and neighbor policy configuration commands

Command syntax

Description

Default

CLI reference


neighbor ipv4-addr remote-as as-#

no neighbor ipv4-addr

Adds an entry to the BGP neighbor table in router configuration mode.

  Adding an entry to the BGP neighbor table in router configuration mode

Parameters neighbor ipv4-addr dynamic

Specifies whether to enable or disable dynamic capabilities.

  Enabling or disabling dynamic capabilities

Parameters neighbor ipv4-addr updated-source ipv4-addr

Specifies the IP address to be used on the local end of the TCP connection with the peer.

  Specifying the IP address for local end of TCP connection with peer

Parameters neighbor ipv4-addr allowas-in num-loops

Specifies the number of times this autonomous system can appear in an AS path.

When not configured, or when using the no version of the command, the value of as-loops is set to its default value of 1.

Specifying the number of times the autonomous system can appear in an AS path

Parameters neighbor ipv4-addr as-override

Causes all occurrences of our peer’s AS to be replaced with one from an export.

  Replacing occurrences of peer's AS with one from an export

Parameters neighbor ipv4-addr ignore-leading-as

Some routers are capable of propagating routes without appending their own autonomous system number to the AS Path.

By default, BGP will drop such routes.

Allowing BGP to keep routes without AS number

Parameters neighbor ipv4-addr local-as as-#

Identifies the autonomous system (AS) that BGP is representing to a peer.

The default AS number for this command is the current AS (configured with the router bgp command in Global Configuration mode.)

Identifying the AS that BGP is representing to a peer

Parameters neighbor ipv4-addr maximum-prefix max-routes

Specifies the maximum number of routes that BGP will accept for installation into the RIB.

The value defaults to “unlimited” if not specified, or if using the no version of the command.

Specifying maximum number of routes for installation into the RIB

Parameters neighbor ipv4-addr out-delay sec

The specified integer represents the amount of time a route must be present in the routing database before it is exported into BGP

Defaults to 0 if no specified or if un-configured by using no version of command.

Specifying the amount of time route is present in database before exported to BGP

Parameters neighbor ipv4-addr weight weight

Preferences are the first criteria of comparison for route selection.

This value defaults to the globally configured preference if it is not specified.

Specifying a route's preference

Parameters neighbor ipv4-addr send-community

To specify that a community’s attribute should be sent to a BGP neighbor, use the neighbor send-community command in address family or router configuration mode.

  Sending a community's attribute to a BGP neighbor

Parameters neighbor ipv4-addr use-med

Processes sending of MEDS and for handling received MEDs.

By default MEDs are used to choose which route to use.

Processing sent and received MEDs

Parameters neighbor ipv4-addr timers keep-alive hold-time

To set the timers for a specific BGP peer, use the neighbor timers command in router configuration mode.

The values of keep-alive and hold-time default to 60 and 180 seconds, respectively.

Setting the timer for a BGP peer

clear ip bgp [neighbor ipv4-addr] [soft]

Resets BGP peering sessions, sends route refresh requests if ‘soft’.

  Resetting BGP peering sessions

Parameters neighbor ipv4-addr ibgp-multihop [ttl]

Enables or disables multi-hop peering with the specified EBGP peer, and optionally indicates the maximum number of hops (TTL.)

  Enabling or disabling multi-hop peering

Parameters neighbor ipv4-addr next-hop-self

Forces BGP to use the router's outbound interface address as the next hop for the route updates to the peer.

  Using the router's outbound interface address as next hop

Parameters neighbor ipv4-addr passive

If enabled, does not initiate a peering connection to the peer.

  Specifying no peering connection to peer

Parameters neighbor ipv4-addr remove-private-as

Specifies whether the private AS # should be removed from the as-path attribute of updates to the EBGP peer.

  Removing the private AS number from updates to EBGP peer

Parameters neighbor ipv4-addr route-reflector-client

Acts as a route-reflector for the peer.

  Acting as a route-reflector for the peer

Parameters neighbor ipv4-addr shutdown

Shuts down the BGP peering session without removing the associated peer configuration.

  Shutting down the BGP peering session without removing peer configuration

Parameters neighbor ipv4-addr route-refresh

Enables or disables the advertisement of route-refresh capability in the Open message sent to the peer.

  Enabling or disabling advertisement of route-refresh capability in open message