Enabling Jumbo Frames on our Core network

[Jeremy_Bullock]

If I enable Jumbo frames on a top of the rack (server farm) and 'above' it on a 'core' switch, will it effect devices that might not support jumbo frames?

[andreas1]

It will not affect devices that hasn't configured jumbo-rames themself. It only allows clients/devices that has it configured to send jumboframes. So it's totally safe to enable on all ports.

[Kawawa]

In addition to what Patrick said, if an upstream/downstream device receives a Jumbo frame, if fragmentation is not allowed for that stream, that frame is dropped. When this happens, you should see the RX Over and Jumbo packet counters increment when you run the "show ports rxerrors" and "show ports packet" commands.

[Patrick_Voss]

Enabling jumbo frames will just allow the switch to process a larger MTU size. It will allow all traffic below that maximum threshold.