Routing and DNS

mws1 · 10-22-2008, 07:48 AM

Hi everyone,

I'm currently assigning new IP addresses to quite a few network interfaces. The whole process includes modifying the OpenVPN configurations and routes.
I wonder if it makes sense to use host names instead of IP addresses when adding routes, e.g.

Code:

route add -host testsystem.mydomain.com gw gateway.mydomain.com

The idea behind that would be to minimize the effort of assigning new IP addresses next time ;-) Technically, this seems to work. But I'm not so sure if it's wise ... Any comments?

Michael

PS: The host names are resolved by a DNS within the local network.

acid_kewpie · 10-22-2008, 07:58 AM

no, the route command will resolve to an ip address on entry. when you later run something like "route" to show the routing table it does a reverse lookup to get a hostname. routing tables only contain ip addresses internally.

chort · 10-22-2008, 08:54 AM

Quote:

Originally Posted by acid_kewpie

no, the route command will resolve to an ip address on entry. when you later run something like "route" to show the routing table it does a reverse lookup to get a hostname. routing tables only contain ip addresses internally.

More specifically, the hostname is converted to an IP at the time you run the command, so it does a one-time conversion. It doesn't ever lookup the hostname again. There's no functional difference between using a hostname and an IP when setting routes.

That should be clear from a_k's post, but I just wanted to reiterate it.

acid_kewpie · 10-22-2008, 11:53 AM

that's what i thought i said, not clear enough i guess. ;-)