IEA Software, Inc.

IEA Software Knowledge Base - ID:57038

IEA Knowledge base

Air Marshal (KB ID: 57038)

Oct 30 2007

Our customers are randomly being disconnected with a termination reason of Port-Preempted, what can cause this?

Oct 30 2007

Air Marshal continually checks to make sure the users MAC address has not changed. If a change is detected the session is disconnected with the message port-preempted requiring the user to re-authenticate. Possible causes of a detected change are:

  • Routers or other devices configured with Proxy ARP enabled. Proxy ARP should be disabled on all customer facing routers.

  • New customer re-assigned an existing sessions address via DHCP

  • Hacking / Attempt to reuse an authenticated IP address.