3

If a managed switch and all attached devices both support VLANs and Jumbo Frames, is it possible to mix VLANs with jumbo frames and VLANs with standard frames on the same switch port / ethernet card?

If it is possible, should I expect it to work in any environment or there are specific items (server ethernet card, ethernet card driver, server operating system, switch brand/model, etc.) that could cause problems in such a mixed environment?

5
  • 1
    You can definitely trunk VLANs with different jumbo frame settings so by extension, I'm confident you could tag them to an access port. What I'm not sure about is how your client device will handle it. I am curious as to why, though - you'd generally give iSCSI / NFS its own access ports / NICs. – Dan Nov 30 '12 at 12:03
  • Check out the bottom part of this doc: communities.netapp.com/blogs/ethernetstorageguy/2009/09/12/… – kubanczyk Nov 30 '12 at 12:31
  • @Dan, we have to aggregate two LANs (currently on independent ports/switches), one is for generic LAN traffic (MTU=1500) and the other is dedicated to a DRDB link (MTU=9000). The port currently used for DRBD will be dedicated to a new iSCSI SAN but we need to keep DRBD going for a brief period to allow migration. Disabling Jumbo on the DRBD VLAN wouldn't be a problem (it's already vastly underutilized), but the whole thing prompted me to reason about the mixing MTUs issue in general and thus asking here on SF. – Luke404 Nov 30 '12 at 13:04
  • @Luke404, how did you end up setting up the network? Did the mixing work? – hvrauhal Feb 12 '18 at 7:20
  • 1
    @hvrauhal yes it did, see my answer :) – Luke404 Mar 15 '18 at 13:35
2

After testing and using it for some months, I can say that yes it works.

The switch MTU settings acts merely as it names suggests, a maximum transfer unit [size]. Increasing it above what a VLAN hosts are actually using will not affect traffic in any way that I know of.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.