Jumbo Frame Support

[librizzs]

We have an app server that is capable of supporting Ethernet frames up to 6K or so. Currently, it has redundant connections to a pair of Cat 4506 (Sup IV, IOS 12.2(25)EWA5) on 10/100/1000 48-port line cards. Both switches have a pair of Gig fiber trunks uplinked to redundant 6509 core switches (Sup 2,IOS 12.2(18)SXF3.) I have reviewed Cisco's documentation on enabling jumbo frame support on these switches, but on how many interfaces would I need it configured? The two interfaces on the 4500 switches are a given, but does it also need to be set on all the aforementioned trunked interfaces? Or does this have to be applied to nearly all datacenter switches, similar to uplinkfast/backbonefast commands?

[azoulflak]

I think you need to enable jumbo frame on all components located on the data path.

if any component in the data path is limited to a 1500 byte MTU the data path will not support Jumbo Frames.

Deployment scenarios of jumbo frame:

· Server-to-Server

· Server-to-Switch

. Switch-to-Switch

. etc ..

[keller.oliver]

Although my opinion is theoretical, I'd say it would be better to either have a complete jumbo frame connection or none at all.

If the server-switch connection features jumbo and the rest doesn't, then the switch has to care for segmenting/fragmenting the jumbos into standard size frames. This may take some load off the server, but puts the load directly on the switch.

But I may be corrected here :).