Additionally, you can also do:
Host foo foo.example.com some.other.alias
Nice tip about the placeholder, I will steal that. Thanks.
Yes that's exactly what I do. I just left it as an "exercise for the reader" to not make the comment too long :)
This kind of stuff is also useful, for example, for AWS machines:
Host ec2-*.compute-1.amazonaws.com
# KeepAlive of 50 seconds, because AWS times out after 60:
# https://aws.amazon.com/blogs/aws/elb-idle-timeout-control/
ServerAliveInterval 50
You can also use placeholders for keys, so for example I have a ssh config like:
I originally started doing this because I would have so many keys that servers would reject me for too many authentication attempts, but it also helps make it easy to use distinct keys for distinct purposes and avoiding fingerprinting like this*