Outbound Firewall Port Scanner

[Roadki11]

Does a utility exist to scan open outbound firewall ports on my firewall? I know many exist to scan for open inbound ports but i want to verify my outbound firewall policy.

Thanks,

RoadKi11

 

[LawnBoy]

I've just run the same utility from inside the firewall.

 

[pansophic]

You would need a target host outside the firewall that would react in predictable ways to determine if your outbound policy is working correctly. It would be hard to determine if a random ephemeral port, like 46622 is responding as closed because the firewall blocked the connection, or if the port was actually closed on the remote host.

For something like this, I would probably resort to netcat and do some scripting. Or maybe a tool like Firewalk, which can test lots of permutations but is EXTREMELY slow.

Normally outbound rulesets are so sparse that a manual approch is not unreasonable.


pansophic

 

[LawnBoy]

You would need a target host ... that would react in predictable ways

Isn't that true regardless of the direction you're scanning?

 

[Serbtastic]

Absolutely!

 

[pansophic]

I only mentioned the external host because most people don't have one to target. They have lots of hosts inside their firewall, but few if any on the outbound side. At least that you can consider "reliable" targets.


pansophic