On the Cisco switches running spanning-tree and BPDU Guard (Bridge Protocol Data Unit) if you plug an Avaya system into the switch it will advertise multiple mac's and IPs which will trigger BPDU Guard to place that port in err-disabled status.

To fix this issue enter the following command on the switch interface the Avaya system is plugged into to correct the err-disabled state for that specific port

spanning-tree bpdufilter enable[/code]

spanning-tree portfast

Definition-The portfast command allows an Ethernet port to immediately transition to the STP Forwarding State when a port “comes upâ€.

spanning-tree bpdufilter enable

Definition-This command prevents ports that are in a Port Fast-operational state from sending or receiving BPDUs. (Enabling BPDU filtering on an interface is the same as disabling spanning tree on it and can result in spanning-tree loops.)

spanning-tree bpduguard enable

Definition-The PortFast BPDU guard feature prevents loops by moving a nontrunking port into an errdisable state when a BPDU is received on that port.

spanning-tree portfast edge

Same as spanning-tree portfast but newer command

spanning-tree portfast bpduguard default

Definition-The PortFast feature is configured on an individual port and the PortFast BPDU guard option is configured either globally or on a per-port basis.

Steps to get to a BGPU Guard standard:

1. If spanning-tree portfast is the standard on all users ports, we would need to add the global command “spanning-tree portfast bpduguard†to all devices that currently do not have this. This will enable BPDU guard for all ports that have spanning-tree portfast on them.
   
2. Remove “spanning-tree bpdufilter enable†…since this command basically prevents ports from receiving/sending BDPU’s
   

The current standard when a new device is refreshed is to put the Global command “spanning-tree portfast bpduguard default†on the new device & “spanning-tree portfast edge†on the user ports.

Also incorporate Error disable recovery.

Proposed commands are:

errdisable recovery cause bpduguard

errdisable recovery interval 300