This can be done on FE interfaces too. Running Cisco FE interfaces back-to-back at 4470 seems to work. I wanted to say that the GE interface below doesn't work with large frames with a certain other vendor's hardware the couple of times we've tried it, and that the default was in fact 1500 for probably that reason. One-off solutions tend to be more trouble than they are worth in big networks. Deepak Jain AiNET On Wed, 14 Jun 2000 jhsu@mur.com wrote:

: : Then again, at least some Cisco gear doesn't think that. : : perdition>sh in g0/1 : GigabitEthernet0/1 is up, line protocol is up : Hardware is Gigabit Ethernet, address is 00d0.7966.eeae (bia 00d0.7966.eeae) : MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, rely 255/255, load 24/255

the last i checked, 1500 was the default. given the right hw & sw, MTU can be adjusted upward. i seem to remember seeing it demonstrated on 12000 gear.

there is a draft [draft-kaplan-isis-ext-eth-02.txt] that discusses some extensions useful to support large frames. these extensions- again, the last i checked- were supported by cisco, and other vendors.

as always, contact your authorized support rep when in doubt.

ymmv,

_k