I have a customer who has 2 2948 running catOS with 3 vlans configured.
One of the vlans is for the internet facing , one for the firewall and the other is a pvlan configuration using the internet facing vlan port as the promicous port for the pvlans. For customers with more than one server instead of wasting pvlan ports the customer connects cat2924s running 11.8 into the isolated port and then connects the servers into the cat2924. He currently has two 2924 plugged into the 2948s. This is a live config and works with out any problems...Until we get a third cat2924 running 12.05 with a clean config and plug it into one of the isolated ports . The ports come up at layer 1 but when layer 2 comes up the two cisco 2948 ports flap grinding the network to a halt.
There are no spanning tree issues and the switches are in vtp transparent mode. One of the errors is packet 1 tag 50 port 2/20 but port native vlan is 100
then certain ports start flapping. .......any ideas?
