I don't know too much about networking and I'm hoping someone can point me in the right direction. I'm not sure how to go about solving my problem...

When I'm connected to my company LAN, I'm able to SSH into my server (CentOS) at home without a problem. However, when I'm connected to my company's VPN, I get a "Network error: Connection refused" error in PuTTY when trying to connect. The PuTTY log tells me the exact same thing and doesn't offer any other information (even when logging raw data). When I'm on the VPN and try to ping my server, it replies so it seems that only communication over the SSH port (22) is failing.

If this is an issue with my company firewall when I'm on the VPN, how would I be able to tell? If it's an issue with my server firewall, how would I be able to tell? Any advice is much appreciated. Thanks!

Edit: I used nmap from the company LAN and VPN just to see what would happen. Here are the results:

From company LAN to server at home:

C:\Users\kal>nmap -p 22 {domain.name}

Starting Nmap 6.25 ( http://nmap.org ) at 2013-03-15 14:04 Eastern Daylight Time

Nmap scan report for {domain.name} ({ip.address})
Host is up (0.066s latency).
rDNS record for {ip.address}: pool-{ip.address}.fios.verizon.net
22/tcp open ssh

Nmap done: 1 IP address (1 host up) scanned in 6.11 seconds

From company VPN to server at home:

C:\Users\kal>nmap -p 22 {domain.name}

Starting Nmap 6.25 ( http://nmap.org ) at 2013-03-15 14:06 Eastern Daylight Time

Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn

Nmap done: 1 IP address (0 hosts up) scanned in 3.84 seconds

  • It might help if you lined out, kind of text-diagram-like, the basic network topography of the different elements. I get hung up in the description with trying to visualize it.
    – killermist
    Mar 15, 2013 at 16:45
  • @killermist I'm not sure what the correct way to draw it would be, but there's only two connections. 1-Laptop A on company VPN connecting to server at home (does not work). 2-Laptop A on company LAN connecting to server at home (works). Hope this clears it up.
    – Kal
    Mar 15, 2013 at 18:01

1 Answer 1


It does seem like it's the company's VPN firewall since you're able to ping successfully. To verify you could try to make your home server's SSH daemon listen at another port (other than the default TCP port 22 for ssh servers to be contacted at). Other than that, only the IT admin can confirm/deny I think.

  • Thanks for the suggestion. I'll try changing the port tonight and see if that works.
    – Kal
    Mar 15, 2013 at 21:09

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