Ran, Did you try adding a community to the prefix, and then try to match on it and set next hop locally on the PE? I did not try it, but can try it later in the lab.
Arie -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ran Liebermann Sent: Saturday, September 20, 2008 13:41 PM To: cisco-nsp Subject: [c-nsp] Blackholing in MPLS VPNs Hi All, Common blackholing mechanisms (such as RFC 3882) rely on the next-hop attribute of BGP, such that the next-hop of the announced prefix will remain the same as the static route even through the BGP prefix is locally originated via the redistribute command. This of course works well when the mechanism is operating in the global routing table of the routers. However when trying to operate the mechanism in an MPLS VPN (for example a VPN for internet traffic instead of the global routing table), then the mechanism breaks down becuase the prefixes are announced with the next-hop as the local router. (output examples at the end of the email). Does anyone have a nice and elegant solution to this? Thanks, -- Ran. For example here is the view of the prefix in the announcing router: ANNOUNCING_ROUTER#show ip bgp vpnv4 vrf INTERNET 2.2.2.2 BGP routing table entry for 64512:100:2.2.2.2/32, version 153 Paths: (1 available, best #1, table INTERNET) Flag: 0x820 Advertised to update-groups: 1 Local 192.168.255.255 from 0.0.0.0 (172.17.17.1) Origin IGP, metric 0, localpref 50, weight 32768, valid, sourced, best Community: 64512:65535 Extended Community: RT:64512:100 mpls labels in/out 33/nolabel And here is the view of the prefix in the receiving router: RECEIVING_ROUTER#show ip bgp vpnv4 vrf INTERNET 2.2.2.2 BGP routing table entry for 64512:100:2.2.2.2/32, version 24 Paths: (1 available, best #1, table INTERNET) Flag: 0x820 Not advertised to any peer Local 172.17.17.1 (metric 20) from 172.17.17.1 (172.17.17.1) Origin IGP, metric 0, localpref 50, valid, internal, best Community: 64512:65535 Extended Community: RT:64512:100 mpls labels in/out nolabel/33 -- Ran Liebermann, VP Engineering, PurePeak [EMAIL PROTECTED] http://purepeak.com _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
