Enterasys Networks X-PeditionTM manual Initial BGP Configuration, Adding BGP Neighbors

Overview

•Permit a local BGP speaker to send the default route 0.0.0.0 to a neighbor as the default route: neighbor default-originate

•Configure the COMMUNITIES attribute to be sent to the neighbor at this IP address: neighbor send-community

•Permit interior BGP sessions to use any working interface for TCP links: neighbor update- source interface

•Permit BGP sessions, even when the neighbor is not on a directly connected segment: neighbor ebgp multihop

•Specify the minimum interval between BGP routing update transmissions: neighbor advertisement-interval seconds

•Configure MD5 authentication on a TCP link to a BGP peer: neighbor password <value>. For an example, refer to “TCP MD5 Authentication for BGP Example” on page 6-25.

•Specify BGP routing updates to/from neighbors, as detailed in an ACL: neighbor distribute-list {ACL#}{in out}

•Set up a BGP filter: neighbor filter-list ACL# {in out}

•Disable next-hop processing on BGP updates to a neighbor: neighbor next-hop-self

•Assign a route map to in or outbound routes: neighbor route-mapmap-# {in out}

•Set the XSR to begin storing received updates: neighbor soft-reconfiguration inbound

•Disable a BGP neighbor or peer group: neighbor shutdown. Conversely, you can enable a previously existing neighbor or neighbor peer group that was disabled with no neighbor shutdown

For configuration examples, refer to “Configuring BGP Peer Groups” on page 6-25.

Initial BGP Configuration

Begin BGP configuration by enabling BGP routing:

•Enable a BGP Routing process and acquire Router Configuration mode: router bgp <AS #>

•Mark a “local” network in this AS, adding it as an entry in the BGP Routing table: network <IP address> mask <subnet>

Adding BGP Neighbors

Adding neighbors to a BGP network is fundamental to building a BGP environment. You can add internal neighbors (those inside an AS) or external neighbors (those in other AS’s). Usually, external neighbors are next to each other and share a subnet while internal neighbors may be situated anywhere in the same AS. The process on the XSR is as follows:

•Add a BGP network: network <IP address> mask <mask>

•Add a BGP neighbor: neighbor <IP address> remote-as <as #>

For an example, refer to “Configuring BGP Neighbors” on page 6-23.

Resetting BGP Connections

If you alter any BGP configuration values that you have defined for BGP neighbors, you must reset that BGP connections for the configuration change to take effect.

•Reset one or more BGP connections: clear ip bgp address

XSR User’s Guide 6-15