11

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?

Improve this question
6
  • @ultrasawblade has a great list of what could be wrong. You'll probably have to get into some specifics of your dad's network setup (i.e. test for some of those problems) in order to get specific help.
    – JoshP
    Jul 18, 2012 at 22:48
  • Coincidentally, my campus had a power outage (which outlasted the long length UPS on the target machine) at the same time as my apartment. So when the power outage forced me to SSH in from my dad's for the first time, it also knocked the target computer out. Verizon was innocent (but they're still bad at math: verizonmath.blogspot.com).
    – Jeff
    Jul 19, 2012 at 2:33
  • Ack! Lol. Glad to hear it was something simple
    – JoshP
    Jul 19, 2012 at 2:43
  • :) glad it worked out for you!
    – user98645
    Jul 19, 2012 at 12:15
  • i found this question today, and then realized that last night i have changed my router firewalls settings, from low to medium.. :)
    – ADM
    May 21, 2015 at 6:12

4 Answers 4

Reset to default
13

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.
Improve this answer
4
  • Thanks for the rundown. I think I can eliminate 3, 4, 5, 6, and 7 (no i-net connection, campus blocking, local firewall or antivirus, and incorrect PuTTY settings, DNS resolution). How would I check if the router or VZ is blocking port 22?
    – Jeff
    Jul 18, 2012 at 22:46
  • Here is a list of public ssh servers: shells.red-pill.eu - I tried the first one and got an SSH prompt. So I now know my port 22 is not blocked. Of course I didn't try to enter a password and actually login, I just wanted to see the SSH login prompt. I was also very polite and did this exactly once ;). Anyway, this way you know if it's specific to anything on port 22 or just connecting to your campus. Next step is to log in to the router and check settings.
    – LawrenceC
    Jul 18, 2012 at 23:51
  • ive gone thru everything on that list and then some and im still getting network error: connection timed out on every single attempt
    – oldboy
    Jun 5, 2018 at 17:43
  • Another possible cause: server firewall settings that whitelist the IP address of the client. Need to change them if my workstation IP address changes. (In other words, remembering the restrictions a past-version of me put in place.) At least DigitalOcean firewall management ergonomics make a bit of sense, Rackspace has descended into madness.
    – Bob Stein
    Jul 27, 2021 at 16:06
0

Simultaneous power outages at my apartment and on campus were the culprit.

Improve this answer
2
  • ur kidding me? lol. im having this issue right now. no power outages here...
    – oldboy
    Jun 5, 2018 at 6:29
  • Not sure how exactly power outage is related to your issue. Does the server get power from your campus i.e. is part of the campus ? If not, then power outage at your residence (home/college) would be the likely cause of the issue & easy to spot. Unless your router is not powered through your residence, or your residence switches to battery in power outage and the battery is setup to not provide power to router, fridge etc.
    – MasterJoe
    Aug 14, 2019 at 19:21
0

PuTTY connects to SecureShell.

Yes, it is probably the router/Internet connection.

It is rare, but some high-class routers have the ability to drop outgoing connections.

I'm not familiar with Verizon, but it is possible they have some kind of proxy through which you connect to the Internet and this proxy doesn't allow outgoing connection.

I had similar problem at work. The work proxy was blocking port 22 (standard port for SSH). I changed it to 443 which is the HTTPS port, and it allowed me to connect to my server. To do this change, you have to modify /etc/ssh/sshd_config and change default port from 22 to 443 and then connect through that. But this requires you to connect to a server in the first place which is impossible as I see it. Or you could very quickly run to the nearest library, modify the SSH configuration file to listen to the HTTPS port instead of the standard port 22 and run back home.

But I think your best bet is to call Verizon customer support and ask them about it.

Improve this answer
2
  • I'm not sure how to do most of what you suggest. I tried changing the Port setting in "PuTTY Configuration" window, just for the heck of it, and had the same reslt (connection timeout).
    – Jeff
    Jul 18, 2012 at 22:48
  • @Jeff Changing it only in Putty doesn't make a difference, you also have to change port on the server. Otherwise Putty is calling number 443 and your server is not answering because it is listening to only port 22.
    – user98645
    Jul 19, 2012 at 6:57
0

I was having same issue

Solution:

1) turn of Antivirus 2) Wait some time before logging in again 3-5 mins.

Done!

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .