Over the past years, I've created a nice hierarchy in DNS to keep my insanity under control. For example, for the POP server we have (pop.barnet) which points with a CNAME to pop2.barnet which point with a CNAME to the dbmail2.barnet jail which point with an A record to the IP addresses of the machine:
So if the machine fails, or the dbmail jail doesn't work anymore, or the dbmail-pop3 program is broken, all we have to do is one little changes in the hierarchy and it is all working again, without disrupting the real operation of the machine.pop 60 IN CNAME pop2 pop2 IN CNAME dbmail2 dbmail2 IN A 18.104.22.168
Since earlier this month we don't have one, but two POP servers! And of course the easiest solution would be: Let pop.barnet be a CNAME to both pop1.barnet and pop2.barnet.
And there starts the trouble:pop 60 IN CNAME pop1 pop 60 IN CNAME pop2 pop1 IN CNAME dbmail1 pop2 IN CNAME dbmail2 dbmail1 IN A 22.214.171.124 dbmail2 IN A 126.96.36.199
Well, I'm (!)@*#()!@*#'d. This is not allowed... Now I have, because it can't be done any different, reintroduced A records for the services....Jun 13 16:17:24 ns0 named: dns_master_load: .db/barnet.com.au:203: pop.barnet.com.au: multiple RRs of singleton type
| Share on Facebook | Share on Twitterpop 60 IN A 188.8.131.52 ; pop1 pop 60 IN A 184.108.40.206 ; pop2 pop1 IN CNAME dbmail1 pop2 IN CNAME dbmail2 dbmail1 IN A 220.127.116.11 dbmail2 IN A 18.104.22.168
|Posted on:||2007-06-13 21:32:01|
|Comment||RFC 1034 says that you SHOULD NOT (their emphasis :-0) chain CNAMEs like that anyway.|
|Posted on:||2008-06-25 05:12:09|
|Comment||Nice !! I was fighting whit this all day !!
Damn DNS ... mucho more work but is ok-