If you are running a 1500 byte MTU path for your GRE tunnels take off 24 bytes for your GRE encapsulation, ie try adding ip mtu 1476 into your tunnel interface, as long as there is no blocking of ICMP in the return path back to the host it should work.
Ben Stefan Hegger wrote: > Hi, > > hope you can help me to solve my problem. We are running some GSR's (cisco > 12008/GRP) with IOS Version 12.0(26)S6. We opened a GRE tunnel to another > location and have problems with the MTU size. > > It seems that the GSR's does not return an ICMP message > indicating "fragmentation needed". > > When we decrease the MTU to 1400 on host, everything works fine. > > Best Stefan > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
