Bob nicely put... The important thing to distinguish as this is a real confusing topic for me is knowing the difference between the control-plane vs data-plane
the control-plane is where the vpnv4 speakers will exchange the NLRI which would include the RD and the RT as an extended community but the data-plane cannot use this information when making a packet forwarding decision therefore the vpnv4 speakers add the vpn label for a customer prefix (called the inner label) to uniquely identify the customer prefix for delivery.....this is a separate process from the (outer label) mpls transport label to get to PE in the first place (ldp/tdp ospf/is-is derived) here is a good visual for control-plane NLRI that vpnv4 speakers would pass to each other, I also note here that label 19 is showing can someone confirm that vpnv4 speakers also pass the inner label to each other via NLRI control-plane? http://4.bp.blogspot.com/_n3Sbk_2ZV-g/TCTtlR2wekI/AAAAAAAAAcY/P_W77wIYxGA/s1600/2.JPG BR Tony On 28 March 2013 13:59, Bob McCouch <[email protected]> wrote: > Are you saying that using the following as an example: > > router bgp 1 > bgp router-id 1.1.1.1 > no bgp default ipv4-unicast > neighbor 1.1.1.2 remote-as 100 > ! > address-family ipv4 > exit-address-family > ! > address-family vpnv4 > neighbor 1.1.1.2 activate > neighbor 1.1.1.2 send-community extended > exit-address-family > ! > address-family ipv4 vrf BLUE > neighbor 2.2.2.2 remote-as 200 > neighbor 2.2.2.2 activate > exit-address-family > > You configured your neighbor like 2.2.2.2 and the solution you were looking > at had the neighbor configured like 1.1.1.2? > > The first question is: Did your solution work? If I understand what you did > right, I'd imagine it did not work. > > The neighbor 1.1.1.2 in my example that is configured under the routing > process and activated under the VPNv4 address family would be for another > MPLS PE peer that you're exchanging VPN labels with (another PE router > elsewhere in the MPLS network). That peering would not exchange 32-bit IPv4 > prefixes, but 96-bit VPNv4 prefixes that include the RD for uniqueness, > along with extended community values to indicate the label used for that > VPN path. > > The example neighbor 2.2.2.2 in the example above would be the CE peer. > This neighbor is configured *only* under the IPv4 VRF address family (not > at the routing process level) and is how the PE builds a BGP peering with > the CE router *within* the VRF. The peer router in this case would be > running "normal" BGP and totally unaware of the MPLS label exchange going > on behind the scenes. > > The VPNv4 address family is a special case for BGP and it's what makes MPLS > L3VPN work. The IPv4 VRF address family configuration under BGP is pretty > much the same as any other PE-CE routing protocol configuration like if you > did an address family under RIP or EIGRP to use those as the PE-CE protocol. > > Does that help? > > Bob > CCIE #38296 > > > On Mon, Mar 25, 2013 at 8:15 AM, Houssam Chahine > <[email protected]>wrote: > >> Greetings, >> >> I have a small question about address family. >> >> In Lab 3 Vol2, the peering is configured under the router process and >> activated under vpnv4 address family. >> >> What i did was configuring the peering under the ipv4 vrf address family. >> >> I would like to know what is the difference between configuring the >> neighbor statement under the router process and under the address family. >> Furthermore is what i did correct or wrong. >> >> Thank you all in advance. >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> >> http://onlinestudylist.com/mailman/listinfo/ccie_rs >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
