Hey guys! I have my web server currently tucked in behind 2 routers that all have firewalls built in. I am looking to further increase my server security, and was wondering what would be a more secure, yet practical solution? A firewall built on another machine running software such as SmoothWall, or using a firewall on the server itself such as firestarter. Or is the two routers with firewalls sufficient and should I be more worried about code exploits rather than open and unattended ports?

Thanks in advance!