jumbo frames configuration

[A.K.]

I am testing 1000 Base-T PCI Gigabit Ethernet cards A4929A.
on my N4000 machines with HPUX 11.00
Is it possible to configure jumbo frames that are different from 9000 for example 4000?

[rick jones]

I am reasonably sure we only support 9000 and 1500, but that's OK. Set the MTU to 9000 on both machines (your switch does support Jumbro Frames yes?), then you can set explicit host routes (man route) that specify a path MTU of less than 9000 bytes. Verify that this "takes" with a netperf -v2 -H test and see that it reports a plausible TCP MSS.

This is the methodology I used in an old paper on the effect of MTU size on web server performance: ftp://ftp.cup.hp.com/dist/networking/briefs/

WebMTU something or other was the filename.