Massive Amounts of DNS lookups for Null

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1

Platform Version
2.4.4.156

Hardware Version
C-8

Multiple times a day the hubitat device (around 1am and 12pm) the hubitat device does 10s of thousands of DNS requests that have no chance of being successful. What can I do to stop this behavior? I am not using the cloud controller, it is currently disabled. The device is wired, and uses DHCP for ip lease, which is static from the server based on its MAC. Before this was happening almost all of the time until I disabled the cloud controller. There are literally 21,000 requests from 12:00:12 to 12:09:22. There were 18,000 requests from 00:24:10 to 00:29:23, 15,000 requests from 00:53:08 to 00:59:23 and 30,000 requests from 01:00:11 to 01:29:28. I've replaced my domain name with "domain" in the sample below.

For example:

Time Type Domain Client
Time Type
2026-04-09 12:09:22 AAAA null hubitat.domain.com 14.8 µs
2026-04-09 12:09:22 A null hubitat.domain.com 23.1 µs
2026-04-09 12:09:22 AAAA null.eth0 hubitat.domain.com 9.3 µs
2026-04-09 12:09:22 A null.eth0 hubitat.domain.com 8.3 µs
2026-04-09 12:09:22 AAAA null.# hubitat.domain.com 7.6 µs
2026-04-09 12:09:22 A null.# hubitat.domain.com 8.8 µs
2026-04-09 12:09:22 AAAA null.domain.com hubitat.domain.com 8.3 µs
2026-04-09 12:09:22 A null.domain.com hubitat.domain.com 12.2 µs
2026-04-09 12:09:22 AAAA null hubitat.domain.com 14.5 µs
2026-04-09 12:09:22 A null hubitat.domain.com 37.7 µs
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2

Apparently the DNS server is rate-limiting the server, the hubitat device is making ~9500 dns queries every minute. From midnight last night to 10:42pm today it was rate-limited 1332 times, and attempted 8062971 queries that were dropped. Wow, this is seriously broken. Note, rate-limiting happens after 3000 queries in my setup, so its actual 1332*3000 MORE queries than this.

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3

@gopher.ny

Maybe same issue as reported here.

4

Yes and it has been reported at least one other time as well

The fix that worked for both of us was to turn this setting off.
image

We both have Asus routers and Adguard Home.
@user1963 curious now, what is your setup?

Also what is "the cloud controller" ???

3 Likes
5

I did already have the well known DNS servers off...it turns out that there was a "null" app that somehow was placed into my applications that didn't show. Doing a custom repo and typing "test" in there cleared it up, and now everything is working as expect...in fact hubitat doesn't even show on the list, whereas before it was 65% of all DNS traffic even at high traffic times.

My setup is behind a 4 port 2.5GBit pfsense firewall.

This is what I meant by cloud controller:
image

6

Either the post is private or was removed, I can't view it :frowning:

7

That thread was in the beta testing category.

What does that refer to in the context of the Hubitat UI?

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8

None of this makes sense to me. Are you talking about HPM?

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9

I’m also unclear on whether the OP’s reported issue has the same underlying cause as what you described previously.

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