We recently acquired a Dell PowerConnect 5548, but it seems it is not working properly. It learns the MAC addresses, but does not seem to be able to use them to forward the packets correctly, i.e. all ports receive the all the traffic (like in a network hub). The switch only works correctly after disabling spanning tree.
We are using default configuration and the firmware version is 22.214.171.124. This behavior happens even if we test with only 3 workstations connected to the switch.
Is that a known bug in this switch? Or maybe we are missing something? I believe that is not a expected behavior for Ethernet switches...
Thanks in advance,
On the 55xx switch Rapid STP (RSTP) is enabled by default. If you have STP on other switches in the network you will want to disable RSTP on the 5548.
Console (config) # spanning-tree mode stp
Also you can look at setting your ports that are connected to clients that portfast is enabled
console(config)# interface gi1/0/1
console(config-if)# spanning-tree portfast
Here is the User Guide for reference on configuring Spanning tree starting page 426.