Hi All, I've completed this lab as it asks, but I am trying to more fully understand WHY it works. In AS 125, R1 is a route-reflector with R2 and R5 as clients. R5 connects to AS 689, and R2 connects to CE (R4). AS 689 is similar to AS 125 with R9 as RR for R6 and R9. R6 connects to R5 (AS 125) via EBGP and R8 connects to CE (R7). R1 and R9 have an eBGP peering as well. The Lab is relating to inter AS VPN I've been able to get R4 to ping R7 just fine. I understand how the labels are passed and whatnot, but what's confusing me is related to the connection between R1 and R2. For better understanding, on all the routers I've configured the label range to be x00-x50, I.e. R1 is 100 - 150, R2 is 200-250, etc. so i can get a feel for what labels i'm seeing. I've enabled 'debug mpls packet' on both routers R1 and R2 and issue the ping from R4 to R7.
Here's what I see on R2 for the incoming packet from CE: *Jan 26 21:40:48.215: MPLS: Fa0/0: recvd: CoS=0, TTL=250, Label(s)=204 *Jan 26 21:40:48.215: MPLS: Se1/0.24: xmit: (no label) This seems OK, a bit odd that there's no label outbound no? Here's where it gets weird in my opinion, here's the output from R1: Jan 26 21:40:12.971: MPLS: Fa0/0.12: recvd: CoS=0, TTL=254, Label(s)=100/505/805 *Jan 26 21:40:12.975: MPLS: Fa0/0.15: xmit: CoS=0, TTL=253, Label(s)=505/805 Ok, so.... how was the packet xmit from R2 as untagged but arrive at R1 tagged with three labels? R1 and R2 are peered with BGP, OSPF, and LDP, there's nothing else between them. Without having to post all of the label bindings etc, anyone have any idea about this 'discrepencie'? _______________________________________________ Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: iPexpert on YouTube: www.youtube.com/ipexpertinc
