github - Git SSH error: "Connect to host: Bad file number"

Question

I followed the git guide but I have this strange issue when trying to connect to github:

$ ssh -v [email protected]
OpenSSH_4.6p1, OpenSSL 0.9.8e 23 Feb 2007
debug1: Reading configuration data /c/Documents and Settings/mugues/.ssh/config
debug1: Applying options for github.com
debug1: Connecting to github.com [207.97.227.239] port 22.
debug1: connect to address 207.97.227.239 port 22: Attempt to connect timed out without establishing a connection
ssh: connect to host github.com port 22: Bad file number

This is my config file under .ssh

Host github.com
    User git
    Hostname github.com
    PreferredAuthentications publickey
    IdentityFile "C:Documents and Settingsmugues.sshid_rsa"
    TCPKeepAlive yes
    IdentitiesOnly yes

Any idea?

Answer 1

After having this problem myself, I found a solution that works for me:

Error message:

    ssh -v [email protected]
    OpenSSH_5.8p1, OpenSSL 1.0.0d 8 Feb 2011
    debug1: Connecting to github.com [207.97.227.239] port 22.
    debug1: connect to address 207.97.227.239 port 22: Connection timed out
    ssh: connect to host github.com port 22: Connection timed out
    ssh: connect to host github.com port 22: Bad file number

You will only see the bad file number message when on windows using the MINGGW shell. Linux users will just get Timed out.

Problem:

SSH is probably blocked on port 22. You can see this by typing

    $nmap -sS github.com -p 22
    Starting Nmap 5.35DC1 ( http://nmap.org ) at 2011-11-05 10:53 CET
    Nmap scan report for github.com (207.97.227.239)
    Host is up (0.10s latency).
    PORT   STATE    SERVICE
    22/tcp ***filtered*** ssh

    Nmap done: 1 IP address (1 host up) scanned in 2.63 seconds

As you can see the state is Filtered, which means something is blocking it. You can solve this by performing an SSH to port 443 (your firewall / isp will not block this). It is also important that you need to ssh to "ssh.github.com" instead of github.com. Otherwise, you will report to the webserver instead of the ssh server. Below are all the steps needed to solve this problem.

Solution:

(First of all make sure you generated your keys like explained on http://help.github.com/win-set-up-git/)

create file ~/.ssh/config (ssh config file located in your user directory. On windows probably %USERPROFILE%.sshconfig

Paste the following code in it:

    Host github.com
    User git
    Hostname ssh.github.com
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_rsa
    Port 443

Save the file.

Perform ssh like usual:

$ssh -T github.com 
    $Enter passphrase for key '.......... (you can smile now :))

Note that I do not have to supply the username or port number.