NAME
hostid - set or print identifier of current host system

SYNOPSIS
hostid [hexnum or internet address]

DESCRIPTION
Hostid prints the identifier of the current host in hexadecimal.
This numeric value is expected to be unique across all hosts and is
commonly set to the host’s Internet address. The super-user can
set the hostid by giving a hexadecimal argument or the hostname;
this is usually done in the startup script /etc/rc.