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I'm working with a Tyan S7010 motherboard, which has a built-in AST2050 IPMI module with KVM-over-IP functionality. The board has 2 physical NICs built in. There appears to be 3 MAC addresses on the system...each NIC has its own, but according the BIOS the IPMI module has a MAC that belongs to neither NIC.

I'm running XenServer 5.5 on the system, and the only way I am able to connect to both the IPMI and XenServer is to have both NICs plugged in. Where I'm confused is that in XenServer it sees both physical NICs and their correct MAC addresses, and it properly identifies which are connected. Even more unusual is if I have only the NIC connected where the IPMI works but XenCenter doesn't I am able to ping some addresses from XenServer but not others.

The only explanation I can come up with is that the IPMI takes over one of the NICs, so you only end up with 1 usable NIC on-board. Does this sound reasonable? Is there any better explanation? Tyan's documentation pretty much sucks.

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So what I'm hearing is that it depends on the manufacturer? Anyone have experience specific to TYAN motherboards? – John Clayton Sep 18 '09 at 13:57

We have a bunch of HP servers that have a similar LOM feature. They have two NIC ports, but one of them has two MAC addresses, one of which gets forwarded to the LOM interface. You can think of it as having a switch inside the network card.

As such, it should not interfere with the operation of the second network interface as far as the OS is concerned.

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Absolutely normal for the built in RAC module to take over the 1st NIC in the server.

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dell's DRACs [5th gen] can use dedicated port or 'share' first of onboard ethernet ports.

when using 'sharing' onboard ethernet port is fully available to windows/linux system, ip-kvm has it's own mac and does not interfere.

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