Intel X520 MTU

[acmcool]

I tried MTU 9000 for X520 in winodws,ubuntu...It does not work..I could get 4000 to work..
Any ideas?

 

[Kristian]

@acmcool
What do you mean with "it does not work"?
No connection?
Slower connection?
Other problems?

I run
1x X520 with Windows 8.1
1x X520 with Windows 10
1x X520 with XPEnology
1x X520 in ESXi 6.0 passed through to a Windows 10 guest
all of them with MTU 9000 (I think 9014)

without any problems

 

[Blinky 42]

I also have several X520-DA2's running 9216 MTU's w/o issue, Direct-attached and through Netgear and Juniper switches.

Are you trying direct-attach between cards or through a switch?
Are you getting errors trying to set the MTU or large packets just get dropped when sent through the NIC?

 

[acmcool]

NFS and CIFS just wont copy with mtu 9000...
I tried both as pass throguh and vmxnet3

 

[cesmith9999]

what is the Jumbo frames setting on your switch?

Chris

 

[acmcool]

MTU on switch is set at 9000

 

[mstone]

are you using vlans? the tags increase the frame size. what kind of switch is it? do any hosts on the network work successfully?

 

[acmcool]

Yes I am using VLAN's..Its a dell 6224 switch...I think one host which has chelsio card works fine...But going to test with chelsio cards on both source and destination later today..Just received my additional chelsio card.

 

[mstone]

Yes I am using VLAN's..Its a dell 6224 switch...I think one host which has chelsio card works fine...But going to test with chelsio cards on both source and destination later today..Just received my additional chelsio card.

If it works fine with another card, then never mind. Otherwise, increase the mtu on the switch (leave it at 9000 on the NICs).

 

[acmcool]

Setup mtu 9100 on switch...that seems to have resolved issue...

 

[miraculix]

Some vendors are a little vague on how to configure MTU with respect to Layer 2 versus Layer 3 overhead. It's possible increasing the switch MTU by 12-22 bytes instead of 100 bytes would have also resolved the problem. Glad to hear you fixed it.