North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Why is RFC1918 space in public DNS evil?

  • From: Matthew Palmer
  • Date: Mon Sep 18 04:07:04 2006

I've been directed to put all of the internal hosts and such into the public
DNS zone for a client.  My typical policy is to have a subdomain of the zone
served internally, and leave only the publically-reachable hosts in the
public zone.  But this client, having a large number of hosts on RFC1918
space and a VPN for external people to get to it, is pushing against this
somewhat.  Their reasoning is that there's no guarantee that forwarding DNS
down the VPN will work nicely, and it's "overhead".

I know the common wisdom is that putting 192.168 addresses in a public
zonefile is right up there with kicking babies who have just had their candy
stolen, but I'm really struggling to come up with anything more
authoritative than "just because, now eat your brussel sprouts".  My
Google-fu isn't working, and none of the reasons I can come up with myself
sound particularly convincing.  Can someone give a lucid technical
explanation, or a link, that explains it to me so I can explain it to Those
In Power?

- Matt