piaware DNS requests

FlightAware ADS-B Flight Tracking
1

I’ve been recently watching dns requests on my network and I noticed that the piaware pi has been making over 65000 dns requests, mostly to resolve the following dns entries,

1.south-america.pool.ntp.org
1.north-america.pool.ntp.org
1.africa.pool.ntp.org
1.oceania.pool.ntp.org
1.asia.pool.ntp.org
1.europe.pool.ntp.org

I understand DNS and NTP requests are not much bandwidth, but I would like to know the source.

2

ntpd? With a pool configuration it will periodically refresh the list of peers, IIRC.

3

Those are the network time protocol (NTP) looking for time servers. Take a look at /etc/ntp.conf – that sets up the configuration for NTP on your system.
The ntp.conf file selects a number of servers from different server pools.

If you want, you can trim that down to four or so.

To see how it’s doing, from the command line, type:

$ ntpq -p

That will show you the time servers you’re connected to, and status. Very low bandwidth, a few kb per minute.

bob k6rtm

4

I forgot to mention I already modified the ntp.conf file to input my local ntp server

pi@piaware:~$ ntpq -p
remote refid st t when poll reach delay offset jitter

* 132.163.4.102 2 u 942 1024 377 0.507 -0.078 2.926

and as far as I know I modified the ntpdate stuff as well.

5

I’m seeing the exact same thing - my DNS logs are full of frequent requests to the same servers:

1.south-america.pool.ntp.org
1.north-america.pool.ntp.org
1.africa.pool.ntp.org
1.oceania.pool.ntp.org
1.asia.pool.ntp.org
1.europe.pool.ntp.org

It looks like PiAware doesn’t respect the values set in /etc/ntp.conf, because I have different NTP servers specified there. Is PiAware running it’s own version of NTP in the background?

6

No, it uses a standard raspbian NTPD and does not do NTP itself.

Do you see the same with a regular Raspbian install? I suspect you will.

7

Sorry, I was wrong about this - it turns out this is unrelated to PiAware. In my case it’s actually the FR24feed software running on the same Pi that is constantly hitting those NTP servers. So it seems that FR24feed ignores /etc/ntp.conf and goes it itself with it’s own NTP implementation. Nothing to do with the PiAware software.

8

No, this is not a standard raspbian thing, I have two other raspberry pi’s running in my household and this is the only one doing this.

This is interesting, I was doing research on this, and I suspect you are correct. I see talk about adding the feature to read ntp.conf, but nothing about them actually doing it. Thanks!