I am scratching my head on this, and it's complicated to explain so forgive me if this sounds confusing I have three switches, two Dell 5324s (Gigabit, managed) and one new Cisco SG100D-08 (Gigabit, unmanaged) which is for the office. Dell #1 is the workshop switch. Dell #2 is the house switch. These are connected with an aggregated link over two good quality Cat5 cables. They're at opposite ends of the house and the runs are quite long, but I get great transfer speeds between them and the links are rock solid. I want to connect the new 8 port Cisco to the workshop switch so the office and workshop are on the same network - the house will be on a different VLAN. Basically, I want to use the Cisco to add another 7 ports to the workshop switch, buut upstairs in the office instead of in the workshop. Sounds easy, yes? It's not, apparently. I have connected the two switches together with two brand new patch cables so it looks like this: Workshop switch -> [patch cable] -> Patch Panel -> Office wall port -> [patch cable] -> Cisco switch... but they will not link. I even tried a pair of crossover cables at each end, but they still didn't link. The 5324 has auto sensing ports anyway so it shouldn't matter. I connected the Cisco to the Dell in the workshop with both a crossover and a straight through patch and they both worked fine. So, by a process of elimination we're down to a bad patch between the workshop panel and the office wall plate, right? Wrong. First I continuity tested the connection, then when that tested fine, connected my office PC to the wall plate with a C5 patch. It connects straight away at 1Gbps. So, anyone got any bright ideas why a PC would link to a gigabit port on the Dell but the little Cisco won't?