The Coastcom is (allegedly, by the telephone company) set to 10mbit Full-Duplex. Unfortunately, I do not have a 10mbit full duplex port on my router. My only two choices are a 10mbit Half Duplex, or a 100mbit Full duplex port. Because of the amount of traffic on my network, Half-Duplex just isn't an option. (We're a small web hosting company. Lots of traffic, in and out. Running at half duplex causes way to many collisions and other such errors, and just about drags the network to a halt.)
I decided to place a bridge between the Coastcom and my router, basically to act as a media converter. I took a spare PC I had lying around that had two NIC's. I set one to 10mbit full, and the other to 100mbit full and bridged the connection. I Connected the Coastcom to the 10 port, and the router to the 100 port, and everything is running fine.
I'd like to remove this PC and replace it with a switch, just for the smaller form factor (1U vs 5U w/ a Monitor, Mouse and Keyboard) and less power usage, which will help out my already straining UPS's.
My problem is that when I seem to be having an issue with the auto-negotiation/auto-sensing of the connection with all of my switches. When I plug the Coastcom unit into a switch that's set to auto, it will connect at 10mbit Half-Duplex. Any unmanaged switch I connect the Coastcom to will connect at 10mbit half.
If I use a managed switch and manually set the port speed and duplex on the switch to 10mbit full, the devices will not connect. No link light, no traffic. The managed switch I'm working with is a 3com Baseline 2226 plus. I also have a Cisco Catalyst 2948G-L3, but I do not believe it supports VLANs, which I would need to create to separate my fiber backbone from my servers.
Does anyone have any idea what's going on with the duplex running this thing to my 3Com switch, or help me figure out what I need to do to get my Cisco Switch to support Vlans? I can give more info about any of the hardware as needed.