$> telnet [IP] 80
- From the CLI of the firewall. You'll see a SYN, SYN/ACK, ACK at least if it connects.
The firewall also has Python on it so you can use Python scripts/commands to get URLs also.
I can access that site through both a 7.0.1.03 and a 8.2.1 firewall through the HTTP proxy.
You have to look in the audit to see if your firewall is blocking some sort of header or response from the server.