I have setup of 4 routers R1 - R2 - R3 - R4 .
They are connected as shown. I have also setup a GRE tunnel between R1 and R4. The tunnel status is up and protocol is up.
I have configured tunnel source and reach ability related configurations in R1,R2,R3 and R4.
Now if I put R1/R4 Tunnel Source Loopback Int, Tunnel Interface and Int connecting R2/R3 in vrf A and also modify the static route to reach Tunnel Destination IP in R4 into a vrf static route the tunnel protocol goes down.
Can anybody help ?
The fact of configuring the tunnel itself in a specific VRF, using the "ip vrf forwaring , doesn't force the IOS to perform the tunnel destination lookup in that VRF. The tunnel destination lookup is still performed against the global routing table by default. Only the "tunnel vrf" command can change the default behavior.
you need to configure "tunnel vrf " under the tunnel interface configuration to tell the tunnel interface that the tunnel destination is resolvable via the specific VRF. By default, the tunnel destination is resolvable via the global routing table.