Guest,
Well, what happens is that the PIX dumps the entire stateful inspection table (knowledge of every TCP/UDP connection through the PIX). This requires that every connection be reset, and re-initiated. If users are authenticated through the PIX they may have to be reauthenticated, and re-create their session.
The Clear arp command, dumps the ARP Cache, which forces the PIX to ARP for every device that is on the Local LAN and requires communication through/with the PIX.
Although this disruption *should* only last a few seconds, it could also cause widespread network unrest, and result in some interesting phone calls.
Hope that helps
-Bryan
