Office 365 and BIND

And now… something completely different. Smile

The other day I was “playing” with setting up Office 365 for one of our clients – they have Linux machines for their DNS servers, and BIND as their DNS solution. As this was my first encounter with configuring BIND by myself, I just wanted to share steps I’ve taken to make it work (in my lab environment) – maybe it will help someone…

DISCLAIMER: I’m not a Linux/UNIX expert! I try to figure out what I need, and then try to make this work… with the help of Internet resources (or experts), of course. There is plenty of resources on how to do this already, but I like to have things in one place if I need them again. Smile

So, I’ve began my experiment with wondering which Linux distribution should I take. After some consulting (thanks, Ingrid Smile), the final choice was pretty easy – Fedora (criteria – had to be relatively easy to use (for non-Linux person like me), had to work in Hyper-V without much trouble, and there should be someone who can help if I got stuck). Smile

After a pretty simple installation process (wizard, Next, …, Next, Finish), I’ve had my Fedora box up and running.

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Now, the more complicated part – setup this box to be BIND server, and load the correct records in it, so that Office 365 can add and verify my domain.

Here are the high-level steps (I’ve used Terminal, with su rights):

1. install few packages to get things up and running:

2. configure the BIND (DNS) server to run at startup:

3. query the firewall rules for UDP port 53 access:

4. open the required firewall ports (list of TCP and UDP ports):

5. edit the /etc/named.conf file:

6. comment the lines that are preventing your BIND server from responding to “outside” requests:

7. add your local subnet to allowed list (and add some forwarders for resolving other domains and records):

8. enable recursion:

9. add your zone and a “pointer” to your zone file:

10. create and edit the zone file specified:

11. add the required records to your zone file (by the instructions that Office 365 gives you; sorry about the formatting):

12. save the files, and check the new zone:

13. restart the service and start using it:

And Office 365 response after this – success! Smile

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Things I’ve learned during this “adventure”:

  • you should be careful about the trailing “.” (dot) in FQDN-s that you are using – if you miss it somewhere, you’ll get errors loading the zone
  • there are great guides that can help you – one of them is BIND9 Server: How to (although I’ve seen it a bit too late Smile)
  • don’t be afraid to ask for help!

I cannot stress this enough – this recipe is not the secure way of doing things – it’s sole purpose is to make BIND work in my lab environment!

If I missed (or misunderstood) something, feel free to comment and correct me.

Cheers!

Updated (20160917): There was a tiny error in my zone file – switched priority and weight fields (thank you, Lenny, for pointing it out).

15 Comments

  1. Hello such, I am following your steps to create a zone to use a subdomain in Office365 in linux (bind9). When I do checkzone shows me an error saying “out of zone” for line MX record.

    Any idea that might be failing? Thank you very much for posting this information! 😉

    Reply
    • Hello Tomy,

      Maybe you have a typo in a zone configuration file or pointing the wrong zone file? (be careful there, it’s easy to make a typo – I’ll recreate the whole thing from scratch, if possible; it’s easier than searching for a “needle…” :)). Thanks for reading!

      Cheers,
      Tom

      Reply
  2. Your tips about the SRV records were invaluable. The way the MS presents that info does not translate well, and there is little other clear documentation about around the net.

    Reply
  3. Thank you! We’re not Microsoft customer and need to migrate some account with a temporary autodiscover set up. This was super helpful.

    Reply

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