Bug #2776
open
e1000g jumbo frames don't work with 82579LM
0%
Description
It appears the e1000g driver does not work with jumbo frames with the Intel 82579LM chipset.
I discovered this issue today with a SuperMicro X9SCM-F motherboard which has an Intel 82579LM and an Intel 82574L. My /kernel/drv/e1000g.conf has the correct MaxFrameSize=3,3,0... but I was experience odd network connectivity issues with only one of the NICs (e1000g1 in this case). I reverted back to the default MTU in sheer desperation and everything started working.
mgbowman@oi_151a4:~$ dladm show-linkprop -p mtu LINK PROPERTY PERM VALUE DEFAULT POSSIBLE e1000g0 mtu rw 9000 1500 1500-9216 e1000g1 mtu rw 1500 1500 1500-9216
I tried various MTUs on the e1000g1 interface and nothing but the 1500 works. Intel says both NICs have Jumbo Frame support so this make me suspect it's a driver issue.
Updated by Enrico Papi almost 10 years ago
on oi-151a4, after setting MaxFrameSize=0 and rebooting in noticed the system has already set MTU to:
dladm show-linkprop -p mtu
LINK PROPERTY PERM VALUE DEFAULT POSSIBLE
e1000g0 mtu rw 9216 1500 1500-9216
(don't know if this should happen)
my 82579LM NIC looks OK according dladm/ipadm status, but the system does not receive/send packets.
setting back MaxFrameSize=0, and rebooting, fixes the problem,
sorry but i can not test further here in this system, for example unplumbing the NIC, or removing active interfaces/links on it and setting a different MTU manually.....
Updated by Matthew Bowman almost 10 years ago
Did you mean after setting MaxFrameSize = 3 and rebooting you noticed the system had already set the MTU? This happened for me as well but I chalked it up to auto negotiated between my JF enabled switch and the NIC.
Just wanted to add that if you have MaxFrameSize=3 and manually set the MTU to 1500 (my current setup), everything works as expected.
Updated by Rich Ercolani almost 10 years ago
Apparently the 82579LM NIC has timing issues that various other e1000 drivers have worked around in other ways - search around with 82579LM and packet loss to find more information.
Updated by Matthew Bowman almost 10 years ago
That's a bit unnerving :-/ I was going to use this NIC on a dedicated iSCSI SAN but now I'm thinking I shouldn't.
Updated by Rich Ercolani almost 10 years ago
With any of the workarounds, it's been perfectly reliable for me on many systems. For whatever that's worth.
Updated by Yuri Pankov over 8 years ago
Jumbo Frames on 82579LM are working in FreeBSD (10.0-BETA), which is a bit strange, given that we use (nearly) the same code.