Dynamic IP | TurnKey GNU/Linux

I am using the hub to handle DNS. The turnkey linux boxes I have running are backing up properly, but are not updating their external IP address when it changes.

How often should they be updating their IP addresses? What process handles that? Do I need to enable a chron job for that?

Replies (2)

OK, I

Reply 1 2016-07-21

OK, I found /etc/cron.hourly/hubdns-update and it seems to fire every 17 minutes. However, it isn't updating. How do I troubleshoot this? Any ideas?

The AWS nameservers have a really short TTL

Reply 2 2016-07-21

But that seems to be ignored/over-ridden by many nameservers. In my experience the DNS provided by ISPs is particularly bad at caching HubDNS domains for long periods of time (literally days in my experience with my ISP). I use Google DNS exclusively now and HubDNS handled domains seem to only cache for 5-10 mins.

Although that only seems to be an issue with existing domains. When I register a new one, it's almost instantly available.

I have spoken with Alon about it and he said that AWS Route53 have introduced some new features which may allow us to make it work much better. Unfortunately though we have such a huge backlog of work that I'm not sure when we'll get to that.

As for troubleshooting I suggest that you install dnsutils ('apt-get install dnsutils') and use dig to check TTLs from the nameservers you are using and see what is going on. If you use AWS nameservers themselves the update is almost instantaneous.