I'm having problems with a Cisco Catalyst 2950 switch, specifically I'm unable to connect to the router/get internet access through it. The setup is as follows:
- WAN connected to Router (MikroTIK model, no actual server here)
- Router connected to Switch 1
- Switch 1 connected via fiber to switches 2 and 3, also Catalyst 2950 models
Connections over switches 2 and 3 work, as far as I can tell, quite well. When attempting to patch a new client on switch 1, however, all I get is an "Unidentified Network" and no DHCP lease. Setting a static IP and the router's IP as DNS server and gateway also does not give network access. This behaviour is consistently showing whether the client runs Windows 7, 8.1 or Ubuntu.
The physical connection seems to be working fine, Wireshark shows me ARP packets aplenty flying around. That is the only thing I see, though. Since several different client OS show the same problem, I'm thinking the cause is somewhere in the network. Is there any way a user could introduce such an error? It does, however, only seem to affect new clients, since I have no angry mob of tenants lynching me for this (recently was volunteered to administrate the network of a housing unit, little prior experience in the field).
I also tried adding ARP entries for clients on the router and vice versa, to no avail. Right now I'm looking to gain access to the switch configuration, and would be grateful for any answer as to which settings might cause it.