[AusNOG] Incorrect DNS setup

[Ben Stewart]

On 5/07/10 10:16 AM, Karl Kloppenborg wrote:
> I have done this again this morning and it got me thinking, how come a
> lot of people have these two cases:
> 
> <snip>
> 
> What I am wondering is:
> 
> A) Why do people leave have these cases?

Laziness, really. See second point.

> B) Where did the use of appending www. to the front of things originate
> from?

Back in the good old days of the Internet, when Gophers roamed the
plains, and we had Archie and FTP instead of this new-fangled
Bittorrent, the WWW was quite a new thing. WWW servers weren't seen as
the be-all and end-all of the Internet, and the 'main host' for a domain
was for a more important service, such as SMTP or FTP.

Before MX records, SMTP mail would be delivered to the hostname after
the @ - that is, the domain's main A record. Frequently, that host would
only handle certain services if the organisation was big enough - WWW
would live on a different box to SMTP; the website would only be
accessible via the www.domain. DNS record. This wasn't such a big issue
when most users of the Internet were technically-minded or academics.

Currently though, best practice seems to be to have either the domain's
main A record point to the WWW server, or have a web server listening
that will give a 302 redirect to the www.domain host. Only broken mail
servers will try to connect to the domain's A record instead of looking
at the defined MXes first..

> C) also I see sometimes www1. or www2. on some websites, can someone
> explain these to me?

Depends on the organisation; some may have a server farm for
load-balancing, and as such, the main www. host will give a redirect to
a single host (to maintain session cookies and the like), or the servers
may have different sets of content.

- Ben

-- 
Ben Stewart
Consultant Software Engineer
Ph: +61 402 089 240
<mailto:ben.stewart at tucuxi.org>