On Wed, Nov 29, 2006 at 02:20:03PM -0800, Ian Anderson enlightened us:
> /etc/sysconfig/network is what assigns the hostname to your particular
> server. This is also where CentOS writes the hostname when you initially
> install the OS.
>
> /etc/hosts provides a mechanism for mapping that hostname to an IP
> address. This is one of several ways to map ip's to hostnames.
>
>
> I use /etc/sysconfig/network to "name" my machines and then enter that
> value into /etc/hosts. i.e.
>
> /etc/sysconfig/network
> HOSTNAME="vpn-gateway"
>
> /etc/hosts
> 127.0.0.1 localhost localhost.localdomain
> 10.0.0.1 vpn-gateway vpn-gateway.mydomain.com
>
> the second entry is an "alias" to vpn-gateway. If you were to ping
> either one you would get a response from 10.0.0.1.
>
> There is an order of operations that CentOS uses to resolve host names.
> By default the first attempt is in the hosts file. If it doesn't find
> anything there is will try DNS, if nothing is there it will try WINS,
> and so on. If you have a DNS server in your network you could add a
> record to resolve vpn-gateway.mydomain.com to 10.0.0.1 and not fill in a
> /etc/hosts value at all. (Providing /etc/resolv.conf is setup to look
> at that DNS server)
>
> Someone correct me if I am wrong, but this is what I understand to be
> correct.
>
>
Not to pick nits, but according to the hosts manpage, you have your aliases
and FQDN's backwards:
For each host a single line should be present with the following information:
IP_address canonical_hostname aliases
And it is /etc/nsswitch.conf that determines the order of search. By default
this is files (e.g. /etc/hosts) then dns, and there may be others like ldap
or nis depending on how you set up the machine.
Matt
--
Matt Hyclak
Department of Mathematics
Department of Social Work
Ohio University
(740) 593-1263