[illumos-Developer] [PATCH] Jumboframes on intel 82573L

Garrett D'Amore garrett at nexenta.com
Thu Sep 9 08:12:03 PDT 2010

Ok, so I'd like to see some more things here.

First, you need to file a bug in the bug database on this.

Second, I'm concerned about the choice for maximum MTU.  If the docs say
9014 (which might be 9K plus an ethernet header), then asking for more
is clearly wrong.  Do the docs include the ethernet header itself as
part of the total count (14 bytes normally)?

9014 as a choice is problematic for another reason: it means 9K plus an
ethernet header, without any room for VLAN tag. 9018 would be much

So, before we accept this change, I'd like to see that you're able to
use all MTUs up to and beyond the size you've requested (9216), and that
you've verified this with testing.

That requires bumping the MTU up to the max value, and verifying that
e.g. ICMP ping of very large packets (say 32K or 64K) are passed
correctly and completely.  You need to change *both* the underlying
ethernet MTU *and* the IP MTU.

Once that is verified somewhere, we can remove the XXX comments and
place them with comments indicating your test results. 

Once this is all done, the ideal thing would be for you to put this into
a workspace and contact me so I can walk you through the process to
integrate it yourself.

	- Garrett

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