Administrator Guide

ip as-path access-list as-path-name
2 Create a AS-PATH ACL lter with a deny or permit action.
AS-PATH ACL mode
{deny | permit} as-regular-expression
3 Return to CONFIGURATION mode.
AS-PATH ACL
exit
4 Enter ROUTER BGP mode.
CONFIGURATION mode
router bgp as-number
5 Filter routes based on the criteria in the congured route map.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | peer-group-name} filter-list as-path-name {in | out}
Congure the following parameters:
• ip-address or peer-group-name: enter the neighbor’s IP address or the peer group’s name.
• as-path-name: enter the name of a congured AS-PATH ACL.
• in: apply the AS-PATH ACL map to inbound routes.
• out: apply the AS-PATH ACL to outbound routes.
To view which commands are congured, use the show config command in CONFIGURATION ROUTER BGP mode and the show ip
as-path-access-list
command in EXEC Privilege mode.
To forward all routes not meeting the AS-PATH ACL criteria, include the permit .* lter in your AS-PATH ACL.
Conguring BGP Route Reectors
BGP route reectors are intended for ASs with a large mesh; they reduce the amount of BGP control trac.
NOTE
: Dell Networking recommends not using multipath and add path simultaneously in a route reector.
With route reection congured properly, IBGP routers are not fully meshed within a cluster but all receive routing information.
Congure clusters of routers where one router is a concentration router and the others are clients who receive their updates from the
concentration router.
To congure a route reector, use the following commands.
• Assign an ID to a router reector cluster.
CONFIG-ROUTER-BGP mode
bgp cluster-id cluster-id
You can have multiple clusters in an AS.
• Congure the local router as a route reector and the neighbor or peer group identied is the route reector client.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | peer-group-name} route-reflector-client
When you enable a route reector, Dell Networking OS automatically enables route reection to all clients. To disable route reection
between all clients in this reector, use the no bgp client-to-client reflection command in CONFIGURATION ROUTER BGP
mode. All clients must be fully meshed before you disable route reection.
210
Border Gateway Protocol IPv4 (BGPv4)