arp poison interesting observation/ possible bug

ericgarnel · ‎10-30-2007

I witnessed something very interesting yesterday.

We had a client attach a device with a static ip which happened to be the same as one of our controller service interfaces, but in a different vlan, but one that the controller has a dynamic interface in as well.

All of a sudden, all the APs on the affected controller started disassociating! It took a while to clear out the arp cache and get things settled down, but it has been stable for 16 hours since we disconnected the wired client.

As the dynamic interface is not actively in use, I have disabled it for now.

irisrios · ‎11-05-2007

Is it a dynamic interface or AP manager interface. In any case make sure that you dont assign the same ip address as the controller.

ericgarnel · ‎11-05-2007

The rogue ip showed up on guest vlan "D", but it was the same ip address as the service interface on one WLC controller. The wlc had a dynamic interface in vlan "D" as well.