I have a tunnel betwen a Cisco 3640 and linux gentoo, the internet acces for the Cisco is from a Riverstone Backbone, so i want migrate that Riverstone backbone to a cisco Backbone (CAT 4507) but the tunnel is presenting problems, i dont have web acces, email, etc, i read and found that the problems is MTU, i tried to change the MTU in the tunnel but present the next error.
% Interface Tunnel9 does not support adjustable maximum datagram size
so i fix the ip mtu and ip tcp adjust-mss and got the same problem
ip address x.x.x.x
ip mtu 1436
ip tcp adjust-mss 1436
tunnel source x.x.x.x
tunnel destination x.x.x.x
tunnel mode ipip
when i do a sh interface got
Tunnel9 is up, line protocol is up
Hardware is Tunnel
Internet address is x.x.x.x
MTU 1514 bytes, BW 2048 Kbit, DLY 500000 usec,
reliability 255/255, txload 1/255, rxload 1/255
i dont know what else do, i tried to fix the MTU in the tunnel and in the inteface Fasth but got the same problem, please your help how i can fix this, any help is welcome.
thanks in advance.