How To change MTU on LAN interface

[LIONEL GRIFFITH]

Cisco 3745 router - I need to change LAN interface from 1500 to 4470 to match WAN interafce mtu. Is this possible?

Got this message when I try to change mtu on FastE interface:

% Interface FastEthernet0/0 does not support user settable mtu.

[Mark Turpin]

Pretty straightforward there. The interface doesn't support changing the MTU. There are some models that just do not support this. It appears the 3745 is one of those.

It might be something changed in later code. It might be on the feature navigator...

-Mark

[Richard Burts]

Unless you have code that supports jumbo frames an MTU of 4470 is not going to work. You do not have that support on this class of router (and not for FastEthernet interfaces).

HTH

Rick