I think what is saving the day is that you have the 'next-hop-self' for the iBGP sessions. As you've already got MPLS Between the ASBR and PE's, the FEC/FIB should be properly tagged.
If you didn't include next-hop-self, then you'll need send-label between the ASBRs so the PE's could do the tagging for the end to end LSP. Play around with those configs and compare the results for both sets with: show ip bgp vpn all labels show mpls forwarding show ip bgp labels BTW: Anybody doing the exam on RTP on the 30th Sep? All the best, Francisco http://www.linkedin.com/in/fbaena From: Jo Knight [mailto:[email protected]] Sent: 09 September 2009 09:45 To: Bryan Bartik Cc: Francisco; [email protected]; [email protected] Subject: Re: [OSL | CCIE_SP] Inter-AS VPN Option B and send-label Hi Guys, Im just working though an Option B lab and have VPNv4 configured between ASBRs. I do not have an IPv4 session between the ASBRs and it is working fine and I am getting the labels on the PE routers (R3 and R6), nor do I have mpls enabled between them. If we need to send-label between ASBRs does that mean we need to activate IPv4 between them? R2 and R4 are the two ASBRs in AS1 and AS2 respectively: R2 ASBR BGP Config router bgp 1 no bgp default ipv4-unicast no bgp default route-target filter bgp log-neighbor-changes neighbor 150.50.24.4 remote-as 2 neighbor 200.0.0.3 remote-as 1 neighbor 200.0.0.3 update-source Loopback0 ! address-family vpnv4 neighbor 150.50.24.4 activate neighbor 150.50.24.4 send-community extended neighbor 200.0.0.3 activate neighbor 200.0.0.3 next-hop-self neighbor 200.0.0.3 send-community extended exit-address-family R4 ASBR BGP Config router bgp 2 no bgp default ipv4-unicast no bgp default route-target filter bgp log-neighbor-changes neighbor 150.50.24.2 remote-as 1 neighbor 200.0.0.6 remote-as 2 neighbor 200.0.0.6 update-source Loopback0 ! address-family vpnv4 neighbor 150.50.24.2 activate neighbor 150.50.24.2 send-community extended neighbor 200.0.0.6 activate neighbor 200.0.0.6 send-community extended neighbor 200.0.0.6 next-hop-self exit-address-family ! Thanks, Jo 2009/8/7 Bryan Bartik <[email protected]> Thanks guys. I didn't have LDP enabled between the ASes. I just reviewed the configuration guide for Inter-as mpls vpn with vpnv4 exchange between asbrs and they don't use it either. http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_vpn_connect_ asbr_ps6350_TSD_Products_Configuration_Guide_Chapter.html On Fri, Aug 7, 2009 at 3:52 AM, Francisco <[email protected]> wrote: Did you check if you had 'mpls ip' enabled on the interface connecting to the eBGP neighbour? As you know there are 3 ways for MPLS to exchange labels: - LDP - BGP - RSVP-TE If you've been enabling mpls on the interfaces connecting eBGP neighbours, then they've changed labels anyway and the send-label command is redundant. I had the same situation with a mock lab in the INE bootcamp. I had Option B working but I was not giving the points because I had not use send-label, even though everything is working (which is why you don't notice any problems :) Considering how picky is the script during the exam I would advise you to use send-label for Option B. For what I've heard the script sometimes checks the output of pre-determine show commands, but as well seeks for specific entries in the configuration, so careful there. All the best, Francisco -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bryan Bartik Sent: 07 August 2009 03:00 To: [email protected]; [email protected] Subject: Inter-AS VPN Option B and send-label I have seen some example of option B (ASBRs exchanging VPNv4 routes) and send-label being used...however I have it working without it. I doubt it is needed because the ASBR's share their own local label for VPN routes with each other and this put in their LFIB. The FEC is actually a VPNv4 route. Topology: R1-R2 are AS100 R6,R7 are AS200 R3 is in VRF R1 ---- R5 ---- | ---- R6 ---- R7 ---- vrf ---- R3 >From R6: Local Outgoing Prefix 604 703 200:1:3.3.3.3/32 >From R5: Local Outgoing Prefix 505 604 200:1:3.3.3.3/32 No routers have send-label and everything works fine. Is there a reason I see send-label used with option B? -- Bryan Bartik CCIE #23707 (R&S), CCNP Sr. Support Engineer - IPexpert, Inc. URL: http://www.IPexpert.com _____________________________________________________________________ Subscription information: http://www.groupstudy.com/list/comserv.html Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: 270.13.16/2240 - Release Date: 08/06/09 05:57:00 _____________________________________________________________________ Subscription information: http://www.groupstudy.com/list/comserv.html -- Bryan Bartik CCIE #23707 (R&S), CCNP Sr. Support Engineer - IPexpert, Inc. URL: http://www.IPexpert.com _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.76/2345 - Release Date: 09/08/09 20:45:00
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