[c-nsp] gre tunnel mtu mismatch

[Mike]

Hi,

I have an ME3600 and an ASR920. Im trying to run ospf over a gre tunnel 
and having issues because OSPF seems to see a different tunnel mtu on 
either end of the link.

On the me3600, the transport MTU is 8976 bytes, while on the ASR920 it's 
1476. The me3600 has most of it's interfaces with a 9216 bytes, while on 
the asr920 the single internet facing interface has a 1500byte mtu.


I have tried setting in the tunnel interface "ip mtu 1476" but I get an 
error:

ip mtu 1476
IP MTU not supported on interface Tunnel0


     This is silly. I have no choice in the matter; the me3600 has a big 
mtu and the asr920 has a smaller one, and no way to influence the 
selection it seems. Surely there needs to be some way to connect 
disparate equipment over a gre tunnel?


Mike-