Sonic Slow DNS Updates

[fssbob]

Hi, this is where I was referred by Sonic Support. I'm not sure it's the best place to ask my question, but I'll try:

As well as being a (very happy) Sonic customer, I'm also a Web Developer. I periodically make DNS changes when moving websites to new hosts, etc. I've noticed that Sonic is EXTREMELY slow updating its DNS for changes--regardless of TTL values. Typically within hours every ISP has updated their DNS--except Sonic, which usually takes 24 hours or more. Why is Sonic so slow?

Thanks.

[conradpino]

https://en.wikipedia.org/wiki/SOA_record
Long before planned time for host move alter SOA record as follows:

• TTL: lover value to lower SOA caching period.
• SERIAL: increment every time zone is changed.
• REFRESH: lower value so secondary servers check primary server frequently.
• MINIMUM: lower value so negative caching is minimized.

Wait for old SOA TTL period for changes to fully propagate. Net change is:

• DNS secondary servers check with higher frequency.
• DNS client resolver servers check with higher frequency.

Restoring old values lowers traffic on your domain DNS primary / secondary servers.

[fssbob]

Thanks. I did that. Resulted in quick updates everywhere I checked--except for Sonic.

[kgc]

There's really nothing special going on in our recursive DNS systems (despite the effort we put in to ensure the lowest possible latency.) At this time, it's a two layer system with L7 DNS caching proxies and a number of back end caching recursive server workers behind those. Everything should be respecting the TTLs.

It would be helpful if you can demonstrate that something is not respecting a TTL from an authoritative server. You should be able to see them count down and refresh.

[fssbob]

Well, it's now two weeks since the most recent migration that was an issue. The DNS change was at 19:58 Pacific time on Feb 3. TTL was set to 15 minutes. All servers shown on https://www.whatsmydns.net/ had updated within 30 minutes. All IP's I checked via VPN observed the update within an hour, as did various human observers at different locations. Sonic didn't update for about 24 hours. This was typical, per my experience.