Dell iDRAC devices tend to have problems negotiating with a switch port that’s at 1000mbit/auto – the device is limited to 100mbit. The quickest way to get it working is to disable auto and just go 100/Full.
/admin1-> racadm getconfig -g cfgNetTuning cfgNetTuningNic100MB=2 cfgNetTuningNicFullDuplex=1 cfgNetTuningNicMtu=1500 cfgNetTuningNicAutoneg=1 /admin1-> racadm config -g cfgNetTuning -o cfgNetTuningNicAutoneg 0 Object value modified successfully /admin1-> racadm racreset RAC reset operation initiated successfully. It may take a few minutes for the RAC to come online again.
After a minute or so from it’s reboot it should pop right up on the network.
source: http://tacticalvim.wordpress.com/2013/03/07/disabling-autonegotiate-on-the-dell-idrac/