bind server problem

Hey all,

I have a caching bind dns (and dhcpd) server running on a Slackware box.
It works great, almost.

My website is hosted off-site.

In a browser when I type: www.example.com it works, I get to my website.
If I type example.com (without the www) it does not work.

Does anyone know how I can set up the dns to make this work?

Thanks

 

Do you want example.com to resolve only when you use your caching name
server, or do you want it to work for everyone, from anywhere? I'm
pretty sure a caching-only name server can't make the latter happen.

/Jorgen

 

Have you got an entry specifically for www.example.com but not for the
general example.com?

 

Not quite sure what you mean. I want it work for all our users behind our
firewall. Our dns server is only available locally. Is that what you
mean?

Thanks,

Julein

 

There's an entry for www and an entry for example.com.

www A 100.10.11.12
example.com A 100.10.11.12

I believe that bind automatically put them in there, is that possible?

Just did a little testing, from a Windows machine here on our network
www.example.com works, example.com does not. This makes no sense to me.

I want both to work, mainly because Google is returning example.com so I
want that to work.

 

Yes, that was what was unclear. The part about users behind a firewall
was missing from the original question.

/Jorgen

 

Unless you've got a good reason to use bind I highly recommend switching
to dnsmasq. It's roughly an order of magnitude easier to configure.

As to your particular problem, it's hard to guess what's going on from
two lines plucked from your config file. But, if those two lines are
really next to each other, I'm guessing they're inside a zone defined
for example.com. If I'm right in that guess, you've defined resource
records for www.example.com. and example.com.example.com. If you
replace the second line with

@ A 100.10.11.12

it should work (the @ says 'use the root of the domain').

Also, if you'd used

example.com. A 100.10.11.12

(note the period after the hostname) is would have worked.

 

What do you mean by "it does not work"? There are at least two different
potential issues here.

1. DNS entries: is there a DNS 'A' record for both www.example.com
and example.com, and do both resolve to the same IP address. (This
is what the other posts here seem to be concentrating on.)

2. Web configuration: many websites these days are configured to be
able to run multiple websites from the same IP address. Consequently,
unless you tell the webserver to accept requests for www.example.com
AND example.com, it won't have any content to deliver to you.

You can confirm #1 by running the following commands and visually
confirming that you get the same external address reported for both
questions:

dig +short a www.example.com
dig +short a example.com

You can confirm #2 either by checking the configuration files for your
webserver, or empirically as follows. First, you need to obtain the
correct IP address for your server. In this example I'm going to assume
it's 10.11.12.13:

(a)

nc -vvv 10.11.12.13 80 # "telnet 10.11.12.13 80"
GET / HTTP/1.0
Host: www.example.com

(b)
nc -vvv 10.11.12.13 80
GET / HTTP/1.0
Host: example.com

In both cases you'll need to hit Return a couple of times at the end
(i.e. there needs to be a blank line after the Host: line).

If you get the same content from both requests then your web server is
configured as you hope. If you don't then it isn't.

Chris

 

Joe,

You are exactly correct in everything you say here, your guesses and
conclusions. Both of your solutions work perfectly.

Thank you very much. I am so glad to get this going.

Thanks again.

 

Chris,

Thank you for this helpful answer. It turns out my problem is #1, dns
entries for my web site were not working, Joe helped me fix that. I like
the "+short a", makes it neater.

And I ran your tests for #2, it turns out the web site is configured to
handle both cases properly which is good to know. Thanks for those
tests. nc is very useful.


Julien

 

No problem.

Nc (aka netcat) is a very powerful tool for building or testing network
connections. It's worth taking a look at its capabilities (don't aim
to memorise the manual though!) so you know what's possible. Socat is
another really useful network tool, but IMO the syntax is complex and
really hard to get one's head around.

Chris

 

You're very welcome!