IPIP-tunnel with 1500 MTU
Mikael Abrahamsson
swmike at swm.pp.se
Thu Jan 11 19:37:15 UTC 2001
On Thu, 11 Jan 2001, Bulger, Tim wrote:
> There is an 'ip mtu' option in the tunnel interface config on Cisco routers
> that you can set to 1500.. This will cause the tunnel packets themselves to
> be ip fragmented outbound on the router, hence shifting the fragmentation
> away from your internal network packets and over to the tunnel packets. I
> know that this works with GRE and IP/IP on Cisco routers running 12.x code.
(config-if)#tunnel mode gre ip
(config-if)#mtu 1500
% Interface Tunnel1 does not support adjustable maximum datagram size
I believe this is only true if you have serial links that support MTU >
1500 all the way between the two routers doing the tunneling, right?
--
Mikael Abrahamsson email: swmike at swm.pp.se
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