We've got network build on unmanaged switches. Network size is about 170 computers.
Sometime ago we expanded our office with a few rooms. So as to connect these rooms to our network we bought catalyst 2960 (C2960-48TT-L if it is important), because we are thinking about migrate whole network to managed switches and VLANs and this C2960 should be first step
But after unpacking and connecting C2960 to our unmanaged switch we've got problem: link between C2960 and unmanaged switch not work.
Computers connected to C2960 see only C2960's network, but not computers connected to unmanaged switches. Computers, connected to unmanaged switches, see only unmanaged network, but not coumputers connected to C2960.
C2960 is in default config. I'd configured only IP address and telnet access from Express Setup. All computers are in one IP subnet. Physical link is ok - LanTester shows no problems and if I replace C2960 with unmanaged switch network works fine.
LED on port which connected to unmanaged switch is amber. In web-interface this port shows: "port is disabled". I'd tried to connect link to another free port on C2960 - result is the same.
How to get link between C2960 an unmanaged switch work?