As mentioned in another thread, don't do this blindly. If there are `Host` or`Match` blocks in the config, this new line will only apply to the last of those blocks.
Hue? There is one on mine. Maybe mine's different because I upgraded from 10.9 to 10.10 to 10.11 whereas you might have started with a later version (or an earlier one)?
You have an /etc/ssh, or just an /etc? I have /etc, which is a symlink to /private/etc, but as I said it has no ssh dir.
FWIW I am on 10.10.5 not 10.11. Maybe there's a change in 10.11. (The article the grandparent links is focused on 10.10 so I assumed that was in the scope of this discussion.)