[MLB-WIRELESS] Melbwireless Digest, Vol 35, Issue 11

[Tyson Clugg]

On Wed, 2008-08-20 at 12:09 +1000, Adam Grigolato wrote:
> Im an experianced DNS admin,

So am I, so there.  :P

> it would be pretty easy to setup a DNS server like that,

Sure would be.  The zone file could be generated the same as a hosts
file.

> the problem with the host file setup is that its not a fluid setup.
> it has to be manually changed whenever there is a network change.

The manual update problem can be solved by using cron to periodically
pull a new hosts file.

> DNS and DHCP over that would be good in that regard to allow for a
> dynamic setup,
> well thats my 32.45 cents :D 

The problem with a central DNS server is that our network isn't well
enough connected to ensure lookups work from any part of the network.
Setting up DNS service master/slave replication on OpenWRT is a bit of
overkill and won't work if no link is available to wherever the master
DNS server is located on the network.  A hosts file can be copied
manually if necessary (yes, so can a zone file but you have to reload
your DNS once done - another step that can go wrong).

In the early stages of the Internet before DNS came to be, there was
indeed a global hosts file.  A hosts file works well when all the
information can be gathered from a single source, such as our node
database.  As soon as you wish to delegate responsibility to multiple
sources, then DNS becomes useful.  At the moment I see no need to
delegate DNS zones to poorly connected nodes throughout the network,
especially since our node database already has all the information
required to generate a decent hosts file.

Also remember that a lot of our nodes are running on less than 8MB of
RAM with limited CPU cycles available, and not everyone is a DNS admin.
Think *simple* and everything is more likely to work the way we expect.

Cheers,
Tyson.