We are implementing Avaya IP Phones in 2960 switches with Cisco Multi-Domain Authentication but there is a strange behavior.
When the Phone is connected to the port of the switch, it puts the port in err-disable state (shutdown) and logs the following message:
05:24:35: %DOT1X-5-SECURITY_VIOLATION: Security violation on the interface FastEthernet0/45, new MAC address 0004.0de1.f533 is seen. f
05:24:35: %PM-4-ERR_DISABLE: security-violation error detected on Fa0/45, putting Fa0/45 in err-disable state
If a PC is connected to the port or the port is configured in single-host or multi-host mode there is no error but the customer need to use multi-domain to authenticate the PC and Phone.
Anyone see this? What could cause the errdisable state?