Hi. I have an Asus router flashed with the third-party firmware Asus Merlin. In there I have a VPN setup and I use the OpenVPN App to connect to my VPN in my router. I was concerned about a possible port that may be open in my router so I checked my IP at Shodan, Censys, GRC Shields Up and even Nmapped my WAN IP from a paid-for VPN and despite all that the port of 1194 appears to be closed/filtered. Now my local VPN works fine, it's just that I'm wondering why the port appears to be closed? How is it that I'm able to make a connection to a port that appears closed?
I did some research and it appears that it's hard to Nmap scan a UDP port and OpenVPN? I read about a magic sting and I sent this magic string hex data via Namp and it sent, but no response.
Code: Select all
\\x38\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
So is this magic string still part of OpenVPN or am I doing something wrong in Nmap?
Very curios to find out why and how this port appears to be closed. I thought it was due to port knocking, but there is no port knocking configuration on my part.
