Have you tried manually setting the speed on the interface? I have seen some instances where the ports just don't negotiate properly, but manually setting the speed works. Try 100 and 1000.  What firmware is the switch running? Here is a link to the most recent. [URL] Is the router up to date?
I'm hoping someone can help me solve a problem that I've been working on for the past two days with no luck.  I have a Dell N3024P layer 3 switch that I'm trying to connect to an AT&T router that is a Ciena model 3930.  I cannot get the connection from the Dell N3024P to come up on any ports except for the out-of-band management port.  I'm using a standard CAT5 cable from the Ciena to the Dell. I've tried connecting the Ciena 3930 to the other ports on the N3024P, but none of them ever show a link light, except for the out-of-band management port.  I can configure the out-of-band management port and set the gateway as the next-hop address and everything works fine.  I can ping other hosts on my network from the switch itself by both host name and IP, I can ping remote subnets on my WAN, and I can ping Internet addresses by both IP and host name.  I do not understand why this only works on the out-of-band management port and no other ports on the Dell N3024P.  What am I doing wrong?  It doesn't matter if I set the ports to access, general, or trunk.  None of them ever come up when plugged into the Ciena, except the OOB port. We have other Ciena 3930 routers connected to Cisco layer 3 switches and the connection works fine, but I cannot get it to connect on the Dell N3024P unless I plug it into the out-of-band management port.  Resetting the switch to factory default did nothing. Any suggestions?  Thanks! 
Problem connecting N3024P to Ciena 3930 router. Only the OOB port shows a link!