Firewall Enumeration

What is a firewall?

Put in basic terms it is a hardware/ software device that filters traffic into and out of your network.  These filters tend to differ (i.e. be less restrictive on the traffic that passes) dependant on the placement of the firewall i.e. usually laxer rules in your internal network.

Firewalls can also take many forms be they integrated at the Network or Application Layer.

Another term that is often used is Stateful i.e. it remembers the traffic and can piece it together to make a decision on whether to let it pass or Stateless, each packet is treated in isolation.

Firewalls have different ports that they utilise as managements aids, hopefully SSH, Port 22 and HTTPS, Port 443 are a good point to start. Checkpoints may use Port 264/265 and the list goes on, you need to consult the manual or Google!

A more detailed explanation and links to associated documentation and RFC's etc. can be found here.

Hopefully the tools I have reviewed will go some way to help you enumerate/ interact with any Firewalls you find.