I have a Pix 520 running v6.2(1) Inside network is 172.16.x..x with about 500 users accessing a mail server on the dmz at 192.168.1.2. Everything works fine, but after a while, I will start to get reports that random hosts on the inside network can no longer communicate with the mail server on the DMZ. You can't even telnet to the mail ports. Other PC's are working just fine. If I do a clear xlate command on the Pix, the "blocked" hosts can immediately communicate with the mail server again. After about 12 hours or so, the problem will re-appear on another set of machines.
This problem never occurs when doing a translation through the outside interface for internet access. Only when communicating with the DMZ.
Anyone got a suggestion as to where/what to look for?
Relevant configs from my Pix.
global (outside) 10 interface
global (dmz) 10 192.168.1.32-192.168.1.250
nat (inside) 10 0.0.0.0 0.0.0.0 0 0
