Re: NameServers, DNS, and BIND

[Anand Buddhdev <arb anand org>]

On Sun, Mar 30, 2003 at 01:39:18PM -0600, Cowles, Steve wrote:

> > If you have only one host and it's your nameserver as well as 
> > your mail server, why add redundancy?  If the nameserver is
> > down, so is the rest of the domain.  It's not up to the
> > registrars to tell you how to configure your domain.
> 
> Point taken - at least the part about the registrars responsibility. But it
> seems like back when I registered my first domain (1996/Network Solutions) I
> don't remember being able to register the same IP for both name servers.
> Maybe I just didn't try hard enough. Anyway, I have since moved away from
> network solutions.
> 
> As for redundancy/failover... I run my own DNS/Mail server on the same box.
> If my end goes down, its nice to know that my secondary DNS server (located
> in another state) will still answer DNS queries for my domains and queue
> e-mail for later delivery. i.e. No DSN is sent. So my domain names are not
> "totally" down even though I have a single point of failure at my end.

Not true. If your mail server is down, what good is a secondary DNS
server going to do by answering with MX and A records for the downed
server? The clients will receive the records, try to connect, get a
timeout, and queue the mail for later delivery (and they may generate
DSNs, which you cannot control). This is hardly different from having
a single DNS server which has failed, because in that case, the SMTP
client will get a soft DNS error from its resolver, and still queue
the mail (and possibly generate a DSN which is not in your control).

-- 
Anand Buddhdev
http://anand.org