PuTTY returns Network error: Connection timed out

I'm using an application called PuTTY to remote into a server.

I can use it from my local library and many other libraries around me (and also from Starbucks, Panera, etc.) and it works.

But I tried to use it today from my dad's house the same as before, and I get the error:

Network error: Connection timed out. 

What could be wrong?

Solution 1:

This means PuTTY cannot make a connection to the server.

Possible causes:

• Verizon is blocking incoming or outgoing traffic/TCP connections on port 22, maybe due to the type of plan you are subscribed to or other reason.
• Your dad's router or 3G/4G hotspot is blocking incoming or outgoing traffic/TCP connections on port 22.
• You have no Internet connection and/or something has suddenly gone wrong with the TCP/IP software on your system.
• Your campus is blocking incoming or outgoing TCP connections on port 22 to/from the specific IP you are connecting from, or one of Verizon's subnets.
• You have a local firewall or antivirus software that is blocking incoming or outgoing traffic/TCP connections on port 22.
• Your PuTTY settings are incorrect.
• Your DNS isn't correctly resolving to your campus's IP address and you are actually connecting to the wrong system.