Netgear XCM8810 Chassis User Manual - Page 713

NETGEAR 8800 User Manual for EBGP multihop. Using the loopback interface eliminates multiple, unnecessary route changes. Looped AS_Path Attribute When a BGP speaker receives a route from its neighbor, it must validate the AS_Path attribute to ensure that there is no loop in the AS_Path. When a BGP speaker finds it's own AS-number in the received BGP route's AS_Path attribute, it is considered as "Looped AS Path" and by default, the associated BGP routes are silently discarded. There are certain cases (such as in a spoke and hub topology) where it becomes necessary to accept and process BGP routes with looped AS_Path attribute. This feature enables you to control the processing of BGP routes with looped AS_Path attribute. You can do the following: • Allow the route with looped AS_Path to be accepted • Allow the route with looped AS_Path to be accepted only if the number of occurrences of its own AS-Number is less than or equal to N, where N is an user-configurable unsigned integer configured • Silently discard the route with looped AS_Path BGP Peer Groups You can use BGP peer groups to group together up to 512 BGP neighbors. All neighbors within the peer group inherit the parameters of the BGP peer group. The following mandatory parameters are shared by all neighbors in a peer group: • remote AS • source-interface • route-policy • send-community • next-hop-self Each BGP peer group is assigned a unique name when it is created. To create or delete peer groups, use the following commands: create bgp peer-group delete bgp peer-group Changes made to the parameters of a peer group are applied to all neighbors in the peer group. Modifying the following parameters will automatically disable and enable the neighbors before changes take effect: • remote-as • timer • source-interface • soft-in-reset Chapter 26. BGP | 713