Jumbo frames doesn't works while supported by the network card
- Hi,
I change the MTU size to 9000 for my network cards, but I'm not able to ping other servers and iscsi devices with packets larger than 1500.
Other non hyper-v servers works fine, so I confirm that my switch and other devices works with an MTU of 9000.
The other bad effect of this non working MTU size is: my hyper-v server is not able to access my iscsi device and cannot the access the disks stored here.
I also try with a size of 5000 but I'm suffering the same issue.
My server is an HP DL360G5, in the past the server was setup with Windows 2008 but now I'm using it for Hyper-V R2 (without Windows 2008). And in the past I was able to activate the jumbo frames.
I have try to activate / deactivate the TCP Offload (chimney) but there is no change.
what can I do?
Answers
Hi,
I recommend that you contact the manufacturer of your network adapter for more details. Thanks for your understanding.
By the way, we have a similar issue with yours, you can refer to:
Jumbo Frames on Server Core
Vincent Hu
- Marked As Answer byVincent HuMSFT, ModeratorWednesday, November 18, 2009 9:35 AM
All Replies
- What network card do you have?
- Broadcom NC373i - 1Gbps
The card has an integrated TCP Offload engine
and can be activated for additional iscsi support. - Not all network adapters with TCP chimney offload (you must enable this feature in Hyper-V because it os off by default) work with Hyper-V. This is quote from the R2 Release Candidate FAQ:
Both VM-Chimney and VMQ require hardware support. These features are only available when using specific hardware NICs (please refer to the section below for supported NICs).
NICs:
For Windows Server 2008 R2 RC,
· VM-Chimney capable drivers are available on the RC media for the following NICs:
o Broadcom Net-Xtreme II 1 Gb/s NICs (Models 5706, 5708, and 5709)
o Broadcom 10Gb/s NICs (Models 57710, 57711)
· VMQ capable drivers are available on the RC media:
o Intel Kawela (E1Q) 1 Gb/s NICs (also known as Pro/1000 ET NICs)
o Intel Oplin NICs (IXE) 10Gb/s NICs (also known as 82598)
To determine which NIC(s) your system has, go to the Windows Device Manager and expand the Network Adapters entry. If one of the above mentioned Network Adapters is listed, then your host should be capable of using the associated networking optimization feature.
Drivers for additional NICs that support these features are expected to be available in the RTM timeframe. Some vendors may produce VMQ-capable or Chimney-capable drivers for their NICs and release them through other channels such as their own support web sites.
· Hi,
Have you tried the suggestion? I want to see if the information provided was helpful. Your feedback is very useful for the further research. Please feel free to let me know if you have addition questions.
Best regards,
Vincent Hu
- Hi,
sorry for the delay, I have not received an alert about this post...
so...
the network card is:
Broadcom BCM5708C NetXtreme II GigE (NDIS VBD Client)
So vm-chimney capable.
So I understand that I can activate the chimneey option and I should not suffer performance issue, but I should improve this.
but what about the jumbo frames? Hi,
I recommend that you contact the manufacturer of your network adapter for more details. Thanks for your understanding.
By the way, we have a similar issue with yours, you can refer to:
Jumbo Frames on Server Core
Vincent Hu
- Marked As Answer byVincent HuMSFT, ModeratorWednesday, November 18, 2009 9:35 AM
