Connecting a 2950 Switch to a 3550 Switch

[Desmond Holoman]

I’m trying to connect a 2950 switch to a 3550 switch. I have tried straight through and crossover cat 5e patch cables and the results are the same. There is no indication on the 2950 switch port and there is a slow blinking amber light on the 3550 switch port. The 3550 switch port is on VLAN 1 and the 2950 switch port VLAN 2. Placing the ports on same VLAN does not change the status. When forcing speed to 100 Mbps and duplex to full, there is no indication on the 2950 switch port and the 3550 switch port turned green.

2950 Configuration …

interface FastEthernet0/23

switchport access vlan 1

switchport mode access

3550 Configuration …

interface FastEthernet0/23

switchport mode dynamic desirable

Any help would be appreciated.

[a.hajhamad]

Hi,

I think all the 3550 ports giga ports, so i think the problem maybe from the cable itself, make sure that it is a good cable, cross and as you mention cat5e.

Abd Alqader

[Desmond Holoman]

The 3550 ports are 1000/100/10 Base-T ports. I did have the techs use 3 different Cat 5e cross and straight through cables. The port seems to be auto-sensing. The results are the same with crossover and non-crossover cables.

[a.hajhamad]

Could you please check the same port (0/23) at the Catalyst 2950 by connecting a PC or another switch?

[Desmond Holoman]

When connecting the 2950 port to a PC, the port functions normally. We have done the same with the 3550 port. Again, it functions normally.