Jumbo Frames and NIC's

HEADRAT · 26 Feb 2008 at 17:59

Hi,

I'm just fiddling about with the MTU size but my NIC's (in seperate machines) show:-

Realtek NIC

Jumbo frames
2KB MTU
3KB MTU
4KB MTU
5KB MTU
6KB MTU
7KB MTU

NVidia NIC

Jumbo frames
1500 bytes
2500 bytes
4000 bytes
9000 bytes

I'm not familiar with the notation on the Realtek NIC, what does a 3KB MTU equate to in old money, 1500 bytes?

Dist · 26 Feb 2008 at 19:59

MTU = maximum transmission unit, meaning the biggest packet size. 3kb is ~3000 bytes

bigredshark · 26 Feb 2008 at 20:01

Well done sherlock

Curiosityx · 27 Feb 2008 at 00:24

A jumbo frame is typically anything larger than the default 1518 bytes, Your switch also has to support Jumbo frame sizes upto 9000 bytes otherwise youll experience difficulties, usually this only works best in server to server communications using network teaming and appropriate managed switches.

marscay · 1 Mar 2008 at 18:30

i used 9K jumbo frames on all my pc's in my gbit lan.

there's less cpu overhead but probably no faster or less latency that i've noticed.