Beware of Broadcom NICs

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Beware of Broadcom NICs - 10/18/2008 3:50:30 AM

marciohumpris

Posts: 362
Score: 2
Joined: 5/1/2008
Status: offline

Hello everyone,

I had a lot of slow down (that my users really felt in Webmail) and it was due to a problem Id like to share with others. The reason for the slow network performance issue (accessing files on a storage server was slower then usual as you could see at times using a DIR command or copying files betwen servers) was broadcom NIC cards I have on all machines with TOE (TCP/IP off load engine) ON. Solution was to disable it.

Solution was:

try to disable TOE (TCP/IP offload engine) on the Broadcom NICS. This could solve your network issue.
use this to disable it:
Netsh int ip set chimney DISABLED

Details:

http://justanothersysadmin.wordpress.com/2008/03/22/dell-broadcom-server-2003-sp2-snp-and-toe/

regards,
Marcio

Post #: 1

RE: Beware of Broadcom NICs - 10/24/2008 8:52:21 AM

corinthian

Posts: 24
Score: 0
Joined: 5/16/2008
Status: offline

Good notice and quite true that it will cause a number of issues.

This issue is not exclusive to Win2k3. The feature is available in the driver/hardware of broadcom (as well as some Intel) NICs and for a Win2k server or similar you will find the same problem. In such a case it is required to disable the feature in the driver as Win2k doesn't have many CLI interface options that Win2k3 has. ( May want to verify that the feature is disabled in the NIC as well.)

We discovered this several years ago with a client who regularly send VERY large emails (several hundred page PDF files). The sessions would time out. Looking closer into things we realized that there were many failed sessions (primarily SMTP).

Older drivers may identify the feature as just TCP offload.

Good notice Marcio... gl all

(in reply to marciohumpris)

Post #: 2

RE: Beware of Broadcom NICs - 10/25/2008 3:56:13 AM

marciohumpris

Posts: 362
Score: 2
Joined: 5/1/2008
Status: offline

Thanks for the extra info, Corinthian. I think via command line disabling chimney did the job.

I see in the NIC driver utility Broadcom Advanced Control Suite 0 regarding statistics of Total offload TCP connections. However, I see Checksum offload set to Tx/Rx TCP/IP Checksum Large send offload enabled. These seem to be subsets of TOE. Should I disable these also?

One more site: http://kb.pert.geant2.net/PERTKB/TcpOffloadEngines

Thanks.

regards,
Marcio

(in reply to corinthian)

Post #: 3