1

Is there a way in Linux to make it so when the DNS client looks up information on a DNS name it would return an IP number, even if it does not exist?

I am creating a testing environment, and I want to be able to resolve domain names that do not exist.

I know I can do this in the host file however I do not want to edit this file for every domain name I try to lookup.

Further clarification on my question is this

Scenario 1: I ping google.com dns lookup google.com and get the real IP number.

Scenario 2: I ping nonexstiantdoamin.com it would return local IP number instead of lookup failing.

Kusalananda
  • 333,661
Quill Littlefeather
  • 33
  • In essence you are asking if the Linux resolver can act as though it is broken and/or hacked. Short answer, no.

    Depending on what you are trying to accomplish and how you are using the resolver (dig, nslookup, C Library like resolver(3)) you can write a wrapper around the lookup and have it supply IPs when the real solution fails. Still, why would you want to have DNS behave as if broken?

     – Deathgrip Aug 07 '17 at 15:24
  • 1
    You could use BIND+the RPZ functionality. https://unix.stackexchange.com/questions/253841/large-zone-file-for-bind9-ad-blocking – Rui F Ribeiro Aug 07 '17 at 17:40
  • Basically i am trying to make it so if a user on our network tries to go to invalid domain it will show a custom error page. – Quill Littlefeather Aug 08 '17 at 15:34

1 Answers1

1

Take a look at dnsmasq. It has an -H option that allows you to add hosts. From its man page:

-H, --addn-hosts=<file>
              Additional hosts file.  Read  the  specified  file  as  well  as
              /etc/hosts.  If  -h is given, read only the specified file. This
              option may be repeated for more than one additional hosts  file.
              If  a  directory  is given, then read all the files contained in
              that directory.
niglesias
  • 193