Conditionally Advertising BGP Routes in a VRF?

June 25, 2008 @ 5:09 am · Filed under CCIE Study

Hi,
Maybe I’m too tired to get the point but to me that’s not the same (please correct me if I’m wrong). With conditionally advertiseing I have the exist-maps or non-exist maps which check if a prefix exist in that routing table or not, and based on that fact, I’ll forward a prefix to a neighbor or not. With route-maps, distribute-lists or filter-list I can only filter based on some facts but not conditionally. Am I wrong with that?? So far, I could not find a solution to do that within a VRF…
Here the description of the DocCD:
Conditionally Advertising BGP Routes
Perform this task to conditionally advertise selected BGP routes. The routes or prefixes that will be conditionally advertised are defined in two route maps, an advertise map and an exist map or nonexist map. The route map associated with the exist map or nonexist map specifies the prefix that the BGP speaker will track. The route map associated with the advertise map specifies the prefix that will be advertised to the specified neighbor when the condition is met. When an exist map is configured, the condition is met when the prefix exists in both the advertise map and the exist map. When a nonexist map is configured, the condition is met when the prefix exists in the advertise map but does not exist in the nonexist map. If the condition is not met, the route is withdrawn and conditional advertisement does not occur. All routes that may be dynamically advertised or not advertised need to exist in the BGP routing table for conditional advertisement to occur. These routes are referenced from an access list or an IP prefix list.
Von: Shaughn Smith [mailto:Shaughn.Smith@za.verizonbusiness.com] Gesendet: Mittwoch, 25. Juni 2008 09:54 An: Roger RPF; ccielab@groupstudy.com Betreff: RE: Conditionally Advertising BGP Routes in a VRF?
Hi
Like I said yesterday. You can use route-maps, distribute-lists and filter lists in your VRF configuration.
Below confirms it
xxxxx(config-router)#address-family ipv4 vrf xxxxxxx xxxxxx(config-router-af)#neighbor 192.168.1.1 ? activate Enable the Address Family for this Neighbor advertisement-interval Minimum interval between sending BGP routing updates allowas-in Accept as-path with my AS present in it as-override Override matching AS-number while sending update capability Advertise capability to the peer default-originate Originate default route to this neighbor description Neighbor specific description disable-connected-check One-hop away EBGP peer using loopback address distribute-list Filter updates to/from this neighbor dmzlink-bw Propagate the DMZ link bandwidth ebgp-multihop Allow EBGP neighbors not on directly connected networks filter-list Establish BGP filters inherit Inherit a template local-as Specify a local-as number maximum-prefix Maximum number of prefixes accepted from this peer next-hop-self Disable the next hop calculation for this neighbor next-hop-unchanged Propagate the iBGP paths’s next hop unchanged for this neighbor password Set a password peer-group Member of the peer-group prefix-list Filter updates to/from this neighbor remote-as Specify a BGP neighbor remove-private-as Remove private AS number from outbound updates route-map Apply route map to neighbor route-reflector-client Configure a neighbor as Route Reflector client send-community Send Community attribute to this neighbor send-label Send NLRI + MPLS Label to this peer shutdown Administratively shut down this neighbor soft-reconfiguration Per neighbor soft reconfiguration timers BGP per neighbor timers translate-update Translate Update to MBGP format ttl-security BGP ttl security check unsuppress-map Route-map to selectively unsuppress suppressed routes update-source Source of routing updates version Set the BGP version to match a neighbor weight Set default weight for routes from this neighbor
—–Original Message—– From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Roger RPF Sent: Wednesday, June 25, 2008 7:46 AM To: ccielab@groupstudy.com Subject: WG: Conditionally Advertising BGP Routes in a VRF?
Hi Group,
Need to ask again…is there no possibility in a VRF for conditionally advertising?
—–Urspr|ngliche Nachricht—– Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Im Auftrag von Roger RPF Gesendet: Dienstag, 24. Juni 2008 15:29 An: ccielab@groupstudy.com Betreff: Conditionally Advertising BGP Routes in a VRF?
Hi Group,
Is it possible to do conditionally bgp route advertising in a vrf? I cannot configure it and I cannot really find information about it. The normal config is as the following:
http://www.cisco.com/en/US/docs/ios/iproute/configuration/guide/irp_bgp_basi c_net_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1055661

But how to do that within a VRF?? Any ideas??
regards
Roger

Bookmark this post:These icons link to social bookmarking sites where readers can share and discover new web pages.