Hello users,

I have a question ?

I was just wondering whether the hostname on unix systems are case sensitive.

For example in the system which I work.

ping TestHost and ping testhost gives me the same output i.e I get the reply from the remote host

Is this applicable for all systems ??

Thanks in advance

ajphaj

it depends how the hostname and literal IP address are configured in /etc/hosts

and if it is not that

nameserver in /etc/resolv.conf

which maps hostname to IP address

My two cents...
When you configure a hostname for the system (make the entries in it's /etc/nodename, /etc/rc.config.d/whatnot files), that hostname is case sensitive. If you configure a system with name UPPERCASE, then the 'uname -n' or 'hostname' commands will give you the output as UPPERCASE. But this remains only on the system that you configure.

On another system, you make the entry of the IP address in the /etc/hosts file and give the system name as 'lowercase', then the system will see that IP address with the hostname 'lowercase'. In that case if you type ping lowercase, you would get a reply, even though the actual hostname of the remote system that you are pinging is UPPERCASE.

from the perspective of name resolution, i do not believe hostnames are case sensitive.