Dynamic DNS via EdgeOS and Cloudflare

May 16, 2017

Networking

Dynamic DNS is an essential tool if you’re your provider is unwilling to provide you with a static address. On almost all residential connections with the large providers you’re not going to be able to obtain a static address unless you convert over to one of their business accounts, then pay some hefty amount like 15USD monthly.

I’ve used several DNS providers and have been with Cloudflare for a good while now due to their literal speed. They have had some incidents, but I don’t use any of their CDN-Reverse Proxy-MITM features so it didn’t cause me any issues. We assume:

you’re using Cloudflare as a DNS provider
you know how to find your Cloudflare api key
You have an EdgeOS device
you’re able to ssh into that EdgeOS device

This is a super short article because this is really easy. The reason I’m putting it in article form, and separate, is that it took me a good deal of time to find the proper commands to set this up. Here are the commands, assuming your WAN is eth0:

configure
set service dns dynamic interface eth0 service custom-cloudflare host-name <SUB.DOMAIN.NAME>
set service dns dynamic interface eth0 service custom-cloudflare login <ACCOUNT_EMAIL>
set service dns dynamic interface eth0 service custom-cloudflare options zone=<DOMAIN.NAME>
set service dns dynamic interface eth0 service custom-cloudflare password <API_KEY>
set service dns dynamic interface eth0 service custom-cloudflare protocol cloudflare
commit;save;

You used to need a server directive, but as of 1.10.5 you no longer need it

Now to test this out:

update dns dynamic interface eth0
show dns dynamic status