[K12OSN] hub vs. switch at eth0

[mo_luscre]

This summer I did a completely new install on a server and lab that has been 
working fine for last 2 1/2 years. I originally had the built in NIC port of 
this Dell 600 Server as eth0. On the new installation it insisted on reversing 
the network cards, so now eth0 is a PCI Realtek NIC. OK, I thought I could 
live with the change, but I am having a baffling problem. All original 
hardware- cabling Amer.com switch and terminals are still in place. Wehn I 
switched the network cables on the server to allow for the changed eth0 the 
terminals could not connect. After many attempts at chaning NIC assignments in 
Fedeora still no connection. By accident I found if I insert a 10 based hub 
(not a switch) in the line between eth0 and the labs 24 port Amer.com switch 
everything works fine, but if I replace the hub with a 100 Switch no go! The 
only way the terminals connect is if there is the hub in the line (it only 
works when I use to standard ports and will not work if I use uplink port. I 
have also tried inserting a crossover cable in place of the hub but no go. I 
have tried a number of switches to check for a bad switch and still no go.

I am stumped

Anthony Luscre
Technology Director
Mogadore Local Schools