Re: [cobalt-users] Colo says need scond server

[Kris Dahl <krislists@xxxxxxxxxxxxx>]

on 7/10/00 4:11 PM, Webmaster at webmaster@xxxxxxxxx wrote:

> At 10:42 10/07/00 -0700, you wrote:
>> 
>> If this is the solution that they suggest, I would highly recommend jumping
>> ship.  They are apparently unaware of methods used to keep DNS servers
>> synchronized--and that is a pretty big deal.
>> 
>> Let me say this: you can automate the process fairly easily.
>> 
> 
> Hi Kris,
> 
> Can you point me any resources on the web for automatic process
> of updating secondary servers.

Heh... Does this count?

http://www.amazon.com/exec/obidos/ASIN/1565925122/o/qid=963273123/sr=8-1/ref
=aps_sr_b_1_1/102-5353993-8548907

This book is considered the BIND bible, and if there was ever a must-have,
this is it.

But I'll give you the basic run-down of the process.

Essentially there are two ways to automate a zone transfer:  refresh time
vs. notify.  A refresh time is simply that: the 'slave' dns server has the
expire/refresh time in the SOA of that domain's record.  When it hits that
expiration date, it polls the master name server, checks to see if there is
a file with a higher serial #, and if so updates its own records.

Notify is only supported with certain software, including BIND 8.  It
doesn't work with NT's naming services AFIAK.  But since we are all running
BIND 8, it should be all good.  This method, the master 'notifies' the slave
name servers that there 'may' be a new file/record.  This essentially
pre-empts the expiration, and the slave polls the master, checks the serial,
if higher downloads file and updates its local record.

However the standard (expire) method is the most popular used, to the best
of my knowledge.

All you need to do is in /etc/named.conf on the slave name server, set it as
follows:

zone "example.com" in {
    type slave;
    file "sec.example.com";
    masters { 192.168.1.1; };
}

This can be done through the Cobalt interface for those of you that are, to
use a technical term, 'wussies'.  By Server Management -> Control Panel ->
DNS Settings -> Add... -> Secondary Name Service for Domain.  Then put the
domain that it will be serving secondary and the IP for the primary.

It should then work automagically... by default the cobalt's set to check
the master every three hours.  This is typical.

For additional resources (beyond Amazon), check out
http://www.isc.org/products/BIND/

Cheers,
-k