Every once and a while a user will be unable to get past the PIX firewall. They can reach all of the internal resources- shared drive, exchange server, printers, but no internet. If I change there IP address to a static one, they can reach the outside world again (until that one goes bad). When IP goes bad, I can't ping anything on the outside, so I don't think it's the DNS. I can even transfer the bad IP to another machine (statically) and the IP still does not work properly. So its not the NIC card. Everything points to the PIX. Has any one had this problem before?
Any suggestions on where to start trouble shooting would be appreciated!