Hi all
I am having a problem understanding an issue I have and in particular the verification of the issue.
The setup I have is based on the INE R&S topology but I have constructed a diagram which you can find here:
https://www.lucidchart.com/documents/view/4beb-20d4-52149a0e-98dc-29fb0a004143
R4 and R6 have a GRE tunnel between them with static routes pointing to a next hop which is the other end of the Tunnel. VPNv4 peerings are esatblished via the Loopbacks and custoemr routes are exchanged.
Now I can fix the issue in a number of ways:
enable mpls and mpls ip on Tunnel 0
change the BGP peerings to peer using the tunnel end points and use mpls bgp forwarding on Tunnel 0
Reset the next hop information to be the tunnel end points using mpls bgp forwarding on the Tunnel
There are pssoible other resolutions but I want to focus on point 1) Enabling mpls ip on the tunnel interface.
My understanding is that without this I cannot send a labeled packet on this interface but how do I see that it is 'broken' using verification commands?
My standard verification went like this:
Rack1R4#sh ip cef vrf VPN_A 212.18.0.0 de
212.18.0.0/24, epoch 0
recursive via 150.1.6.6 label 47
recursive via 141.1.46.6 unusable: no label
Rack1R4#sh ip cef 150.1.6.6 de
150.1.6.0/24, epoch 0
local label info: global/27
recursive via 141.1.46.6
attached to Tunnel0
Rack1R4#sh ip cef 141.1.46.6 det
141.1.46.0/24, epoch 0, flags attached, connected, cover dependents, need deagg
Covered dependent prefixes: 3
need deagg: 3
attached to Tunnel0
1) However when I enable mpls ip on the tunnel interface my customer pings start working but nothing in the above verification changes so what additional verification should I be looking at?
2) Why when I am peering via a loopback does the mpls bgp forwarding not allow me to send labeled packets using the labels I learnt from VPNv4 yet it does when they peer directy or I modify next hop?
Nick