How to set up an alias server name

I want to set up an alias server name on my laptop (Linux). I do not want to use the /etc/hosts/ file since the IP address of the remote server changes. The reason I want to do this is because the server name is 27 characters long. I want to do this:

ssh server

Instead of:

ssh server.subdomain.domain.com

I have several subdomains that I use. How do I set this up?

PS: I do not consider this a dupe because other similar answers do not address the fact that an IP address will change.

Use file ~/.ssh/config

example content:

Host jane
HostName long.server.name
User root

then you can use ssh jane instead of ssh [email protected]

If IP address changes and you do not know the revDNS of this server you can try to use command host 1.0.0.1 where 1.0.0.1 is the IP address - this wil give you current revDNS name that you will be able to configure.

If hostname (reverse DNS) changes with the ip change or your server is behind a NAT - you can either use Dynamic Dns (dyndns.org) and/or use port forwarding.

In order to use the shorter "ssh server" instead of "ssh server.subdomain.domain.com" you simply need to append "subdomain.domain.com" to the search field in /etc/resolv.conf. If there is no search field you can create one.

For example - suppose your /etc/resolv.conf looks like this:

search domain1.com domain2.com domain3.com
nameserver 1.2.3.4
nameserver 5.6.7.8

Modify the search line to look like this:

search domain1.com domain2.com domain3.com subdomain.domain.com

You can place subdomain.domain.com at the front of this list if you want it to be searched first.

If this is just for ssh, you can configure a 'short cut' name in ~/.ssh/config

After that is done then ssh server will work every time assuming the fqdn resolves to an ip address.

For details, see http://kb.mediatemple.net/questions/1625/Using+an+SSH+Config+File or the man page for ssh_config.

You could add an alias in your .bashrc or .zshrc:

alias server1='ssh server1'

With server1 added in your ~/.ssh/config for example:

Host server1
Hostname address
User username-on-this-server