Network-based firewalls are not the only type of firewall you may discover along the way. Web Application Firewalls, or WAFs, are very commonly used to protect web-based applications. If you are unfamiliar with an environment, detecting a WAF can help lay out the web application infrastructure. To help us figure out this bit of information, we are going to utilize a tool called WAFW00F. WAFW00F can help you determine whether there is that extra layer of security prior to the web servers.
WAFW00F can detect the presence of a lot of different WAF types. By running the wafw00f command with the -l flag, you can see list of currently defined WAFs. Here is the current list from my lab. If one of these is not detected, don't fret; the wafw00f command will still inform you that a generic WAF has been detected:
Profense
NetContinuum
Incapsula WAF...