connect a cisco 3550 switch to a dell switch

To do this you will need to use 802.1q trunking?
This link will explan how to trunk the 3550.
http://www.cisco.com/warp/public/473/88.html

Without knowing the model of the dell switch I  can't even guess if it would. You need to post COMPLETE infomation especially when asking about internetworking devices from different MFG's

Best to work up the stack when troubleshooting

You have used the correct cable? There are link lights on each switch that are blinking now and again.

As Mark suggests, have you got any VLAN opperating on either switch that might be splitting up the broadcast domains.

Third, have you got the clients on the same subnet as the server, or configured the layer 3 part of the switch correctly. i.e can you ping from one side to the other?

That should get you to a stage where you know whats what.

Hope that helps,

FatLad

cant the cisco switch ack as a dum switch and just allow traffic?

depends what you mean by "dumb switch", the nature of a switch is that it will perform filtering of MAC addresses before transmitting packets, otherwise it is a hub.

The Cisco switch can be set up to be a normal layer 2 switch, but it may also do a lot more, some of which may result in the problems experienced by fbrown333

Are you using a straight-through cable or a crossover cable to connect the 2 switches? You need a crossover cable. There is no reason why the 2 shouldn't work very nicely together as long as the cable is right and you don't have one of the ports configured to do something "smart" like trunking.

thats what I mean as a hub, but theres a catch..... I know about cross over and stright but the cisco switch is in a different room then the dell

You can go up to 100 meters on 10/100 Ethernet. either use patch panels with regular Cat-5 in between, or buy a long cable and a kit to make your own crossover on one side. Just swap pair 1-2 with pair 3-6, which usually is the orange and green pairs.