We've starting ordering iDRAC Enterprise cards for all of our new servers. We do a lot of remote support for clients, and these cards give us complete remote control for the server via a dedicated network interface. With this, we can control all of the BIOS level stuff that we used to go onsite for. When some clients are an hour or two away, this saves a ton of time for us and clients.
Yesterday, I got a new server in and the iDRAC was behaving oddly. When I plugged in the network cable to the iDRAC network interface, the link light came on and it blinked for packets as it should. However, I couldn't connect to the default IP addresses of the iDRAC. In the status for the iDRAC, it was configured to use the dedicated network interface but said "No Active LOM".
Thinking that this might be an issue with the card not being seated correctly, I reseated the card. After reseating the card I had no link light on the network interface at all. Then I configured it to use one of the onboard network interfaces and it worked fine. So, at this point, the problem appears to be the dedicated network interface.
I popped it open again to take a look. It turns out that the dedicated network interface for the iDRAC is a small card that plugs into the motherboard. On this server, it was loose. After reseating the dedicated network interface, all was good.
I found a couple other references on the internet to fixing this by having Dell replace the motherboard or by changing firmware on the iDRAC. This reference provides documentation in case reseating doesn't fix it for you: