Help in connecting 3COM and Cisco switches
Posted on 2008-06-19
We have a small network here at a plant. In the office there is a Catalyst 3750 switch and that in turn is connected to a 3COM 2426 Baseline Switch (3C16491) out in the plant. There are 3 other 3COM switches in the plant connected to the "main" 3COM switch that connects back to the office.
We are getting some poor performance on this network. There are also 3COM 3102 IP Phones (3C10402B) that everyone has in the company. Ping times from my machine in the office to the 3COM "main" switch range from 5ms to 700ms. Physically the switch is about 100ft from me so the ping time shouldn't be that high. The ping times will be low for a few seconds and then spike for a few seconds and just keep repeating this pattern. I did not setup this network, so I'm just now starting to take a look at what is really going on. There are only around 50 pc's total and same with the IP phones, so this network should really be moving fast.
My question is the following:
1. In the plant with the 4 3COM devices (3 are in different parts of the plant and connect back to the one "main" 3COM switch that connects via fiber back to the office), what should the ports be set to? Should I have link aggregation turned on the "main" switch in the port that each connects to?
2. Should I turn on link aggregation for the fiber port on the "main" plant 3COM switch back to the Cisco 3750 in the office? And what should be my port settings on the port of the 3750 that connects back to the 3COM?
From reading the manuals of each switch, I cannot explicitly set the speed and duplex. The 3COM is hardcoded to be 1000/auto (it negotiates to 1000/full) and the 3750 is coded to auto/auto (it negotiates to 1000/full). There is no spanning tree or switchport configured on the 3750.
I'm kind of at a loss as to what could be causing the ping times to just cycle like that and then to hear from people in the plant that things are just terribly slow all the time. Like I said, I'm new here and trying to see what's up with this network. The equipment here seems to be good and with the amount of users they have, it should be a fast network in my opinion.
Thanks for your help!