TCP Chimney Offload supported network adapters

[Nayax]

Hi

According to this KB :

https://kb.vmware.com/selfservice/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=1465

I need to have a Virtual Switch that is bound to one or more of the following network adapters in order to get TCP Chimney working:

• Intel PRO/1000 with a MAC type of 82544 or greater
• Broadcom BCM5700 series card, chip type 5702 or greater (except 5705_A0)

My network adapter is:

INTEL I350 GIGABIT NETWORK CONNECTION

Does that necessarily mean I cant run it?

I'm a bit confused...

Thanks

[MKguy]

The KB seems confusingly worded and outdated.

The key here is that the reference adapters are specified as "this or greater". These are really old NIC chips and pretty much all of today's server NICs do support TSO.

To check the host TSO state you can run these commands on the shell/SSH:

~ # esxcli network nic tso get

NIC     Value

------  -----

vmnic0  on

vmnic1  on

vmnic2  on

vmnic3  on

vmnic4  on

vmnic5  on

~ # ethtool -k vmnic0

Offload parameters for vmnic0:

Cannot get device udp large send offload settings: Function not implemented

Cannot get device generic segmentation offload settings: Function not implemented

rx-checksumming: on

tx-checksumming: on

scatter-gather: on

tcp segmentation offload: on

udp fragmentation offload: off

generic segmentation offload: off

~ # ethtool -k vmnic2

Offload parameters for vmnic2:

Cannot get device udp large send offload settings: Function not implemented

Cannot get device generic segmentation offload settings: Function not implemented

rx-checksumming: on

tx-checksumming: on

scatter-gather: on

tcp segmentation offload: on

udp fragmentation offload: off

generic segmentation offload: off

On Windows you should use vmxnet3 and run this command to check the current state:

C:\> netsh int tcp show global

Querying active state...

TCP Global Parameters

----------------------------------------------

Receive-Side Scaling State          : enabled

Chimney Offload State               : disabled

NetDMA State                        : disabled

Direct Cache Access (DCA)           : disabled

Receive Window Auto-Tuning Level    : normal

Add-On Congestion Control Provider  : none

ECN Capability                      : enabled

RFC 1323 Timestamps                 : disabled

Initial RTO                         : 3000

Receive Segment Coalescing State    : enabled

Non Sack Rtt Resiliency             : disabled

Max SYN Retransmissions             : 2

If it's disabled, you can enable it on Windows with:

netsh int tcp set global chimney=enabled

[bpayne1]

Updating this for newer versions of Windows server. Netsh has been deprecated, use the following:

PS C:\> Get-NetOffloadGlobalSetting

ReceiveSideScaling : Enabled
ReceiveSegmentCoalescing : Enabled
Chimney : Disabled
TaskOffload : Disabled
NetworkDirect : Enabled
NetworkDirectAcrossIPSubnets : Blocked
PacketCoalescingFilter : Disabled

PS C:\> Set-NetOffloadGlobalSetting -ReceiveSegmentCoalescing Disabled

PS C:\> Set-NetOffloadGlobalSetting -Chimney Enabled

PS C:\> Set-NetOffloadGlobalSetting -TaskOffload Enabled