Mac – Unable to restart ssh on Mac OS Sierra – launchctl unload Could not find specified service

macport-forwardingssh

I am trying to tunnel into a remote EC2 bastion server via ssh because I need to connect to a DB behind a firewall.

In the document linked above, in section Remote port forwarding, it says

There is one more thing you need to do to enable this. SSH doesn’t by
default allow remote hosts to forwarded ports. To enable this open
/etc/ssh/sshd_config and add the following line somewhere in that
config file.

So I changed GatewayPorts no ===> GatewayPorts yes and attempted to restart SSH as it stated. It recommends sudo service ssh restart, but I'm on Mac OS Sierra.

This SO Post says I can start/stop ssh via

sudo launchctl unload (or load) /System/Library/LaunchDaemons/ssh.plist

but get error

/System/Library/LaunchDaemons/ssh.plist: Could not find specified
service

Things I've tried:

This article says LaunchAgents is run as a user, not root, which I am doing.
/System/Library/LaunchDaemons/ssh.plist exists
launchctl has subcommand load and unload

So what's the problem?

Best Answer

You can restart openSSH on your mac with the following (tested on Sierra 10.12.6)

sudo launchctl stop com.openssh.sshd
sudo launchctl start com.openssh.sshd

Related Solutions

MacOS Sierra – error: The specified item could not be found in the keychain – within ssh

It's hard to say for certain without seeing the actual full command, but I'd guess that you're probably running into quoting issues because the command gets passed through two shells (local shell -> ssh tunnel -> remote shell -> codesign command). Each shell interprets and removes quotes and escapes before passing strings on, and you want those double-quotes to be interpreted by the final shell, so you may need to add another layer of quotes. Here are some examples:

ssh user@server codesign --force --deep-verify --verbose --sign "CERT NAME"

This doesn't work because the double-quotes are interpreted and removed by the local shell, so the final command (effectively) has the cert name unquoted.

ssh user@server 'codesign --force --deep-verify --verbose --sign "CERT NAME"'

This works because the outer (single-) quotes are removed by the local shell, leaving the inner (double-) quotes to be interpreted by the remote shell, so it'll pass the entire cert name to the codesign command as a single argument.

ssh user@server "codesign --force --deep-verify --verbose --sign \"CERT NAME\""

This also works, but here double-quotes are used for both the outer and inner layer, so the inner layer needs to be escaped.

Macos – ssh: Could not resolve hostname – High Sierra

Here's a work around that helped in this case:

# install openssh from brew
brew install openssh

# /usr/local/sbin shouldn't be writable on High Sierra (by default), 
# so brew will fail to link the ssh binary

brew unlink openssh
ln -s /usr/local/Cellar/openssh/<version of openssh>/bin/ssh /usr/local/bin/ssh

That linked a version of ssh that's usable. My coworker is now able to connect as expected. Since there are now two versions of ssh on his mac, it's important to make sure that the openssh version installed via brew is found on the PATH first, eg.

PATH=/usr/local/bin:/usr/bin

Related Question

Macos – launchctl unload say: Could not find specified service