Administrator Guide

DellEMC(conf)# seq 10 permit 10.10.10.0/24 ge 32
DellEMC(conf)#exit
DellEMC(conf)# router bgp
DellEMC(conf-router_bgp)#neighbor 10.10.10.2 distribute-list route10 out
The commands show the conguration of an IP prex list named route10, which permits routes to network 10.10.10.0/24. The neighbor
command congures to use IP prex list route10 to determine, which routes to be distributed to the neighbor 10.10.10.2. So the routes
from 10.10.10.1/24 network is distributed to neighbor 10.10.10.2 since the IP prex list route10 explicitly permits the routes to be distributed
to the neighbor.
To view the BGP conguration, use the show config command in ROUTER BGP mode. To view a prex list conguration, use the show
ip prefix-list detail or show ip prefix-list summary commands in EXEC Privilege mode.
Filtering BGP Routes Using Route Maps
To lter routes using a route map, use these commands.
1 Create a route map and assign it a name.
CONFIGURATION mode
route-map map-name [permit | deny] [sequence-number]
2 Create multiple route map lters with a match or set action.
CONFIG-ROUTE-MAP mode
{match | set}
For information about conguring route maps, see Access Control Lists (ACLs).
3 Return to CONFIGURATION mode.
CONFIG-ROUTE-MAP mode
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 | ipv6-address | peer-group-name} route-map map-name {in | out}
Congure the following parameters:
• ip-address or ipv6-address or peer-group-name: enter the neighbor’s IPv4 or IPv6 address or the peer group’s name.
• map-name: enter the name of a congured route map.
• in: apply the route map to inbound routes.
• out: apply the route map to outbound routes.
To view the BGP conguration, use the show config command in CONFIGURATION ROUTER BGP mode. To view a route map
conguration, use the show route-map command in EXEC Privilege mode.
Filtering on an AS-Path Attribute
You can use the BGP attribute, AS_PATH, to manipulate routing policies.
The AS_PATH attribute contains a sequence of AS numbers representing the route’s path. As the route traverses an AS, the ASN is
prepended to the route. You can manipulate routes based on their AS_PATH to aect interdomain routing. By identifying certain ASN in the
AS_PATH, you can permit or deny routes based on the number in its AS_PATH.
Border Gateway Protocol (BGP)
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