Connect with SSH through a proxy

Question

I have no real idea what I\'m doing here so please bear that in mind if you can help me!

I am trying to connect to my virtual server through a proxy but I can\'t con

Answer 1

$ which nc
/bin/nc

$ rpm -qf /bin/nc
nmap-ncat-7.40-7.fc26.x86_64

$ ssh -o "ProxyCommand nc --proxy <addr[:port]> %h %p" USER@HOST

$ ssh -o "ProxyCommand nc --proxy <addr[:port]> --proxy-type <type> --proxy-auth <auth> %h %p" USER@HOST

Answer 2

Here's how to do Richard Christensen's answer as a one-liner, no file editing required (replace capitalized with your own settings, PROXYPORT is frequently 80):

 ssh USER@FINAL_DEST -o "ProxyCommand=nc -X connect -x PROXYHOST:PROXYPORT %h %p"

You can use the same -o ... option for scp as well, see https://superuser.com/a/752621/39364

If you get this in OS X:

 nc: invalid option -- X
 Try `nc --help' for more information.

it may be that you're accidentally using the homebrew version of netcat (you can see by doing a which -a nc command--/usr/bin/nc should be listed first). If there are two then one workaround is to specify the full path to the nc you want, like ProxyCommand=/usr/bin/nc ...

For CentOS nc has the same problem of invalid option --X. connect-proxy is an alternative, easy to install using yum and works --

ssh -o ProxyCommand="connect-proxy -S PROXYHOST:PROXYPORT %h %p" USER@FINAL_DEST

Answer 3

For windows, @shoaly parameters didn't completely work for me. I was getting this error:

NCAT DEBUG: Proxy returned status code 501.
Ncat: Proxy returned status code 501.
ssh_exchange_identification: Connection closed by remote host

I wanted to ssh to a REMOTESERVER and the SSH port had been closed in my network. I found two solutions but the second is better.

• To solve the problem using Ncat:

  1. I downloaded Tor Browser, run and wait to connect.
  2. I got Ncat from Nmap distribution and extracted ncat.exe into the current directory.

  3. SSH using Ncat as ProxyCommand in Git Bash with addition --proxy-type socks4 parameter:

     ssh -o "ProxyCommand=./ncat --proxy-type socks4 --proxy 127.0.0.1:9150 %h %p" USERNAME@REMOTESERVER
     

     Note that this implementation of Ncat does not support socks5.

• THE BETTER SOLUTION:

  1. Do the previous step 1.

  2. SSH using connect.c as ProxyCommand in Git Bash:

     ssh -o "ProxyCommand=connect -a none -S 127.0.0.1:9150 %h %p"
     

     Note that connect.c supports socks version 4/4a/5.

To use the proxy in git commands using ssh (for example while using GitHub) -- assuming you installed Git Bash in C:\Program Files\Git\ -- open ~/.ssh/config and add this entry:

host github.com
    user git
    hostname github.com
    port 22
    proxycommand "/c/Program Files/Git/mingw64/bin/connect.exe" -a none -S 127.0.0.1:9150 %h %p

Answer 4

ProxyCommand nc -proxy xxx.com:8080 %h %p

remove -X connect and use -proxy instead.

Worked for me.

Answer 5

I use -o "ProxyCommand=nc -X 5 -x proxyhost:proxyport %h %p" ssh option to connect through socks5 proxy on OSX.

Answer 6

If your SSH proxy connection is going to be used often, you don't have to pass them as parameters each time. you can add the following lines to ~/.ssh/config

Host foobar.example.com
    ProxyCommand          nc -X connect -x proxyhost:proxyport %h %p
    ServerAliveInterval   10

then to connect use

ssh foobar.example.com

Source:

http://www.perkin.org.uk/posts/ssh-via-http-proxy-in-osx.html