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Intel Dual NIC - only 1 works at a time

Last response: in Networking
May 19, 2012 7:35:35 AM

I have installed an Intel PRO/1000 MT Dual NIC into an HP Elite 8200 box on which I'm running Citrix Xenserver 6. The HP box also has an onboard NIC which works fine.

I'm having problems with the dual NIC. If I plug a cable into one or the other, but not both at the same time) that NIC lights up and shows as connected in the XenServer console. But as soon as I plug a cable into both NICs neither of them lights up and XenServer seems to lose sight of both of them.

Why can't both work simultaneously? Do I need to run an Intel utility of some sort on them to configure/flash them in a certain way for a Linux box (XenServer is based on Red Hat)?

I have also tried getting them both to work when booting into a Linux Live CD so I don't think it's a XenServer problem. I have also found that the exact same problem exists when the dual NIC card is installed in a Windows 7 system - one of the NICs will work, but as soon as you plug a cable into both the lights go out. So it doesn't seem to be an operating system issue.
May 20, 2012 12:16:33 AM

das_stig said:
You need to setup the nics as a team so they are both active at the same time, also has the advantage of load balancing.

Thank you for that suggestion. Are you sure it's the answer to what I'm trying to do here, though? I followed the link and it was all about teaming in a Windows Server environment. I'm running XenServer which is based on Red Hat Linux. Also, from what I could gather, teaming is a technique to consolidate 2 physical NICs into one in order to achieve fault tolerance and increase network throughput. What I want is separate NICs on the box which will be on different subnets.
May 23, 2012 2:35:13 PM

For the record, I solved this - but only be buying a new dual NIC card. I got an HP NC7170 card and installed that and it all worked fine.