DNS Issues

Busthead · February 17, 2021, 6:44pm

I recently migrated DNS services to Cloudflare Gateway and have been tweaking associated firewall and NAT rules.

Hubitat (v2.2.4.158) is displaying several DNS errors in the logs:

Other systems on the same subnet can resolve the hostnames without issue:

; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> api.netatmo.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52834
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;api.netatmo.com. IN A

;; ANSWER SECTION:
api.netatmo.com. 832 IN CNAME front-azure.netatmo.net.
front-azure.netatmo.net. 3599 IN A 51.145.143.28

So what gives?

toby · February 17, 2021, 9:05pm

Did your DNS server IP change? If so, you may need to update it on Hubitat

https://community.hubitat.com/t/firmware-update-2-2-5-no-longer-resolving-internal-names/62925/37

Busthead · February 17, 2021, 9:44pm

Internal DNS server IP did not change. The DNS servers assigned by internal DHCP server did change.

http://hubIPaddr/hub/advanced/resetResolvConf?nameserver=DNSipAddr

doesn't appear to be valid on v2.2.4.158.

toby · February 17, 2021, 11:21pm

Support will have to confirm, but I think on the earlier versions Hubitat was hardcoded to use 8.8.8.8 and later versions allow you to set a custom DNS server. Did you create any filters to block outbound DNS?

Busthead · February 17, 2021, 11:36pm

I changed the DNS server on my desktop (same subnet as Hubitat) to 8.8.8.8 and I have no issues. I suspect Hubitat needs its DNS cache flushed. Is there a way to do this? I've already tried rebooting.

SmartHomePrimer · February 17, 2021, 11:45pm

That's not valid in 2.2.4
You'll need to update to 2.2.5.131