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I can control my server command line using PuTTy on my home network (port 22). I can also do this remotely (port 22). Now the issue is that while I am at school, port 22 is blocked on the router so I cannot access the server while I am there.

I was wondering if there is a way to have PuTTy use a different port (443, 80, etc) so that I can control my server command line while I am at school. Will I be able to have putty use port 443 at school (outgoing connection) and then connect to port 22 on my home router?

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I think it could be as simple as forwarding your router port 443 to your computer port 22.... Then you configure PuTTy to connect to your IP / your server name over port 443.... unless I am missing something else.

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Do port forwarding on your home router, for example map router (public IP curl to get it) port 2222 (as long as it is NOT blocked) to your server LAN IP's port 22.

NOTE: Similar to VirtualBox NAT Port Forwarding Rules if you have played with VirtualBox before.

Then at school you can use ssh -p 2222 user@ROUTER_PUBLIC_IP or putty (specific 2222 instead of 22) and ssh to you home server.

NOTE: avoid using common ports like 8080, 443 as it may already be in use by the router.

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The only port open at school is 443... So I'm not sure if this will still be possible – Schmidty15 Sep 6 '13 at 2:47
You can use nmap to quickly scan your router and see the open ports. If it is not occupied, you are good to go;-) – Terry Wang Sep 6 '13 at 2:57
I believe that it is being used because we use HTTPS. I tried logging in from an ssh client on my iPod and it crashed the app immediately – Schmidty15 Sep 6 '13 at 3:09
Not all routers use HTTP over SSL/TLS. Are you nmap scanning the router IP or your school gateway? – Terry Wang Sep 6 '13 at 6:06
I just did and 443 is the only one of 1000 ports open. It says it is https – Schmidty15 Sep 6 '13 at 22:19

An Nmap scan doesn't necessarily give you a 100% accurate picutre of what ports are blocked on a firewall. You can't simply scan the network interface of the firewall to discern the rules. You need to pass traffic through the firewall to do that. So you could use Nmap with a host on the Internet and then scan the IP of that hose, which would in turn send traffic through the firewall and exercise any port blocking rules. But you'd need something on the other end like wireshark to validate for sure whether the packets made it there because simply getting a SYN/ACK back doesn't prove things 100%.

The easiest way to test for blocked outbound ports is with IsMyPortBlocked.

You can manual tests that will cause traffic to be send from the IsMyPortBlocked Java applet (which downloads to your PC) out to the server, over each specified port.

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