SSH sessions hang after VPN reconnect

sshterminalvpn

I am a new user to OS X (MacBook Air, 10.6.7) migrating from Ubuntu and extremely happy with it. I use terminator running on X11 for my terminal program, and I'm using SSH: OpenSSH_5.8p1, OpenSSL 1.0.0d 8 Feb 2011

My problem is that when tunnelblick VPNs reconnect all my SSH sessions hang and I must close the terminal and re-open it. In Ubuntu what would happen is the sessions would automatically continue working again once the VPN connection was re-established.

Is there any way to make it so these connections re-establish once the VPN is back up? Occasionally my VPN hiccups and its annoying to close all my windows. I'm aware I could use screen but it doesn't really solve the problem as easily as it was working under Ubuntu.

Best Answer

Unfortunately, I think each VPN client will be picky about this in its own way. Since the network is dropping from underneath the SSH connection, you will have three scenarios that could cause it to "hang", or just drop (that I can think of).

Data is flowing back and forth, and the connection is gone.
You get a new IP address when reconnecting.
Timeout/Alive conditions trigger before you reconnect.

2 Suggestions...

Use screen (you said you don't want to do this, I know, but it really is the most robust solution. There are scripts out there that can greatly enhance/automate the reconnection process).
Compare your SSH configurations. Usually stored in /etc/ssh_config or similiar.

BTW -- I don't think you should need to close windows, just do "~ ." (tilde dot). Tilde is used to control the ssh session. See the manpage for more details.

Related Solutions

MacOS – Getting VPN to auto-reconnect on connection drop

You could use the following AppleScript, save it as an application and set it to be a agent (no dock icon).

This script will setup a VPN connection when there is none. Therefore, it should also reconnect shortly after your connection drops. You can change the interval to check your VPN connection, it's 120 seconds in the script.

on idle
    tell application "System Events"
        tell current location of network preferences
            set myConnection to the service "VPN University"
            if myConnection is not null then
                if current configuration of myConnection is not connected then
                    connect myConnection
                end if
            end if
        end tell
        return 120
    end tell
end idle

I've explained how to set this up in this answer.

Auto open 4 terminal sessions and SSH them to a given host

You could try creating a profile for each tab (changing Shell > Run command), opening tabs for each profile in some window, and then saving the window as a window group. See this answer.

Or use an AppleScript like this:

tell application "Terminal"
    activate
    do script "echo 1" -- this always opens a new window
    tell application "System Events"
        keystroke "t" using command down
    end tell
    do script "echo 2" in window 1
end tell

Best Answer

Related Solutions

MacOS – Getting VPN to auto-reconnect on connection drop

Auto open 4 terminal sessions and SSH them to a given host

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