Jo, This is what I found as well. Basically there are multiple scenarios for option B, also know as option 2. In the book "MPLS Configuration on IOS Software" this particular scenario is described as "Option 2a: ASBR-ASBR Approach Using Next-Hop-Self Method" on page 288.
On Wed, Sep 9, 2009 at 3:41 AM, Francisco <[email protected]> wrote: > 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 > -- Bryan Bartik CCIE #23707 (R&S), CCNP Sr. Support Engineer - IPexpert, Inc. 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