localhost vs localhost.localdomain

[blastus]

I'm not sure if this is the correct place to post but what is the difference between localhost and localhost.localdomain? Why is there even a localhost.localdomain to begin with?

[XQC]

I'm not sure if this is the correct place to post but what is the difference between localhost and localhost.localdomain? Why is there even a localhost.localdomain to begin with?
Agreed, this host name really does look out of place, espicially for a new user of Linux.

[jdong]

localdomain is the domain that localhost belongs to... UNIX systems need a default domain in addition to just a name.

[Keffin]

Since I just answered a question relating to this... Is there a reason why localhost.localdomain comes before localhost on the first line of /etc/hosts? Because if not it would be nice to switch them as default, giving one less problem in connecting an app (Java at least) to a MySQL database.

[blastus]

I must say that MySQL makes this unnecessarily complicated and fragile. Let's say your hostname is "ubuntu" and your /etc/hosts file has this line...


127.0.0.1 localhost.localdomain localhost ubuntu

...then "localhost.localdomain", "localhost", and "ubuntu" should ALL resolve to 127.0.0.1 and they should ALL be equivalent hostnames. So in MySQL, if you have given permissions to root@localhost, then you should be able to login to MySQL or use any of the following as hostnames in a JDBC connection string; "127.0.0.1", "localhost", "localhost.localdomain", and "ubuntu."

Personally, I don't even know why MySQL bothers to use the /etc/hosts file since it can't even determine that...


localhost.localdomain = localhost = ubuntu