Sounds like you are running out of address in your nat pool. I am going to guesst that you do not need to reload or pc the pix to clear up some connections. You could issue a "clear xlate". This will DROP ALL CONNECTIONS.
You need to look at your global statement. You could use PAT if your address pool is very small. By default the PIX will use NAT until the last address is handed out. Then use PAT on the last address in the pool until an address is opened. The default time out for address to return to the pool is 3 hours.
global (outside) 1 interface
This will force the PIX to use pat for your outbound traffic.
Can you cut some of the config into a replay? I would like to see a "sh hard" and the config fromt he global down to the timeouts. I find it strange that it only stops working during period of high usage.
What happens with you issue: "sh cpu usage"
I guess that you could just be running out of connections... What is the hight number when you issue: "sh xlate"
This sounds like a great time to get the syslog server up and running. Let you see what is going on.
Login to the FXOS chassis manager.
Direct your browser to https://hostname/, and log-in using the user-name and password.
Go to Help > About and check the current version:
Check the current version availa...
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...