On Wed, Apr 20, 2016 at 01:50:44AM -0500, Brian Knight wrote:
At $DAYJOB we use MPLS VPNs from other carriers to provide Internet access to customers connected to these VPNs. There is always a primary path for outbound access, plus one or more backup paths. I am trying to configure a backup path, but can't seem to set AS path prepending on the default route we announce to the MPLS VPN.This is our first time configuring these types of MPLS VPNs on IOS XR. I've got a config that looks a little something like this: -------- route-policy BACKUP-IN apply IPV4-RESERVED-DENY apply IPV4-DEFAULT-DENY # For backup, localpref = 350 # set local-preference 350 set community BGP-SITECODE additive end-policy route-policy BACKUP-OUT # For backup, prepend = 2 # # Announce only default route if destination in (0.0.0.0/0) then prepend as-path MY-AS 2 set community BGP-SITECODE else drop endif end-policy router bgp 53828 neighbor THEIR-IP remote-as THEIR-AS address-family ipv4 unicast default-originate route-policy BACKUP-IN in route-policy BACKUP-OUT out send-community-ebgp send-extended-community-ebgp soft-reconfig inbound maximum-prefix 500 80 restart 1 -------- The config originates a default route towards THEIR-IP, which is expected. But the default route that is generated is apparently not influenced by the BACKUP-OUT policy (prepend MY-AS 2 times). RP/0/8/CPU0:AR1.ATL1#sh bgp ipv4 u nei THEIR-IP adv Wed Apr 20 01:00:39.545 CDT Network Next Hop From AS Path 0.0.0.0/0 0.0.0.0 Local i What's the simplest way to prepend AS path on a default route advertised to a single peer? A few sources suggest adding a default route to Null0 in our Internet routing table and advertising it through redistribution, or enter a "network 0.0.0.0/0" command in the BGP address-family, both of which can be influenced by route policies. Neither of those options sound particularly simple to me. I have also tried the following to no avail: --------- route-policy DEFAULT-BACKUP-OUT prepend as-path 53828 2 set community BGP-SITECODE end-policy router bgp 53828 neighbor THEIR-IP address-family ipv4 unicast default-originate route-policy DEFAULT-BACKUP-OUT --------- I'd be grateful for any insight.
you need to apply a policy at the default-originate statement to do stuff to the originated default on the outbound: default-originate route-policy blah _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
