Recently some of our users complained not reaching some sites. So I did some steps to isolate the problem.
1. ISP port -> Single workstation (I was able to reach any site without any problem).
2. ISP port -> Router -> Single workstation ( Like the first setup, no problem encountered).
3. ISP port -> Router -> PIX 515 - > Single workstation (This is where the problem showed. Some sites returned an error: The connection was reset. The connection to the server was reset while the page was loading.)
What could be the problem with our PIX 515? Please note that this issue showed only recently. I already rebooted the PIX but did not help.
Cisco PIX Firewall Version 6.1(2)
Cisco PIX Device Manager Version 1.1(2)