3750 jumbo frames mtu setting

[rsblind01]

I have a few switches here that I'd like to setup jumbo frames. I've been told that the setting should be over 9000 bytes. In looking at a couple of my switches, I have a 6509 in a large branch that is has the mtu set to 9198. My data center switches where I want to set this up have a setting of 9000 on a stacked core 3750 and a 10 gig Nexus is set to 9216 per its instructions.

In setting up jumbo frames for my VM network best practices state that it should be set a bit above 9000 due to some overhead. So, I'm curious on my 3750... Can I set this higher or is 9000 the limit say to match my Nexus at 9216?... All the reading I find for this just states 9000.

Thanks in advance.

RS

[Joseph W. Doherty]

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Posting

There's no real standard for how large jumbo might be, so different platforms might allow different maximums.  Also, some platforms will support setting MTU to anything from 1501 up to their maximum, some only support a maximum setting.

What I would suggest, for your 3750, set to correspond to what all your devices can support (commonly) for max MTU, or just set to whatever maximum the device allows.  If only the latter, you'll have to watch for one device sending larger MTUs than another device can support.