What is a single-dot-domain in the query log?

[bloblo]

Hi there,

I have a pi-hole running on a raspi for about 1,5 years and I am very happy with it.

Today, I discovered something quite unusual:

a whole bunch of connections to a domain which consists of a single dot:

They started this morning at 09 am and appear quite regularly, exactly every 5 minutes:

through the whole day.

Only one client is contacting this "single-dot-domain", a recently bought Xiaomi Dumbphone for my daughter (it was a X-mas present - and I must admit I haven't checked the logs earlier this week).

I only find these queries in the Query Log, there is nothing about this single-dot-domain in the longtime queries.

Does anybody have any idea what this might be? I'm completely lost (and I haven't found anything here in the forum nor elsewhere in the internet).

Strange enough, these queries stopped about 20 min. ago, but the phone is still actively used.

I'd be really grateful for any hints.

Thanks and keep ad-blocking going.

[jfb]

@bloblo

a whole bunch of connections to a domain which consists of a single dot:

This is the root zone (the top level of the internet).

Likely a poorly programmed app making queries to this domain.

DNS root zone

[bloblo]

Thanks for your quick and very helpful answer. So there is no reason to become nervous or to try to block it.

I learnt something new. Thanks again.

[jfb]

@bloblo

there is no reason to become nervous or to try to block it.

The query harms nothing, no reason to worry. If you did block it, you would block access to the entire internet for all your connected clients.

[bloblo]

It is unblockable via the GUI

[jfb]

It's not unblockable, but you don't want to block it. This regex will block the entire internet

.*