Configure DNS server to return same IP for all domains

Question

I would like to configure a nameserver that will return the same IP address ("A" record) for any arbitrary host name. For example:

example.com
subdomain.example.com
someotherdomain.com
anyotherdomain.co.uk

should all return the same IP address. Is there a way to do this with BIND? Or is there an alternative to BIND that can do this?

score 22 · Accepted Answer · answered Jun 08 '12 at 18:11

22

With BIND, you need a fake root zone to do this. In named.conf, put the following:

zone "." {
    type master;
    file "/etc/bind/db.fakeroot";
};

Then, in that db.fakeroot file, you will need something like the following:

@ IN SOA ns.domain.com. hostmaster.domain.com. ( 1 3h 1h 1w 1d )
  IN NS <ip>
* IN A <ip>

With that configuration, BIND will return the same IP address for all A queries.

answered Jun 08 '12 at 18:11

Oliver

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Works fine, but the main domain doesn't get resolved ? Any ideeas ? eg : testdomain.com – opc0de Jan 07 '14 at 20:59
This works pretty darned well. The only issue is NS record queries for the domain might explode - namely that it serves the NS records for the `.` zone, which won't respond for any given domain's NS queries. (But it otherwise works to serve the proper A record) – Thomas Ward Oct 03 '17 at 18:18
any way for microsoft DNS server? – Hassan Faghihi Dec 24 '19 at 18:17

score 9 · Answer 2 · answered Jun 08 '12 at 15:42

9

According to the dnsmasq man page

address=/#/1.2.3.4

should do the trick.

answered Jun 08 '12 at 15:42

Gerald Combs

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Thanks! That was so simple. Dnsmasq is definitely easier to configure than BIND. – balexand Jun 08 '12 at 16:09
Do you know if there's also a way to use a wildcard with MX records in dnsmasq? – balexand Jun 14 '12 at 18:15
It looks like `mx-host` and `mx-target` will do this. – Gerald Combs Jun 14 '12 at 18:49
1

Do you know how? The use of wildcards with `mx-host` and `mx-target` is not documented in the man page and I can't get it to work. I've tried using similar notation to the `address` option(`#` sign). I've been able to get wildcards working with both `A` and `MX` using BIND using Oliver's suggestion, but I'd actually prefer to use dnsmasq. Thanks! – balexand Jun 15 '12 at 22:55
dnsmasq is more of a recursive nameserver than an authoritative one (could be used parly like that, but clearly not its main goal) – Patrick Mevzek Aug 09 '18 at 20:46
This answer was absolutely perfect for my use case :) – Ceisc Sep 28 '20 at 08:36

score 1 · Answer 3 · edited Aug 09 '18 at 20:45

1

You can do wildcard matching in bind.

*.example.com.        IN      A       192.0.2.45

This has to be defined in your named configuration file for the domain. Just be carefull if you need to define other A records for the domain.

edited Aug 09 '18 at 20:45

Patrick Mevzek

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answered Jun 08 '12 at 16:50

Francois Wolmarans

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3

What part of "all domains" did you miss? – ceejayoz Jun 08 '12 at 18:29

score 1 · Answer 4 · answered Aug 09 '18 at 21:57

1

You can also use the tool fakedns. The usage is very simple - it will bind to post 53 UDP and serve the same IP to all A queries. You provide the IP address as a command line parameter. By far the easiest solution. Requires Python to run.

answered Aug 09 '18 at 21:57

Konrad Gajewski

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Configure DNS server to return same IP for all domains

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