Diversion Lots of DNS queries with Diversion

  • ATTENTION! You'll notice a Prefix dropdown when you create a thread. If your post applies to one of the topics listed, please use that Prefix for your post. When browsing the thread list you can use the Prefix to filter the view.
  • ATTENTION! As of November 1, 2020, you are not able to reply to threads 6 months after the thread is opened if there are more than 500 posts in the thread.
    Threads will not be locked, so posts may still be edited by their authors.
    Just start a new thread on the topic to post if you get an error message when trying to reply to a thread.

Markfree

Regular Contributor
I've updated my RT-AC86U to the latest firmware 386 with a full reset and installed Diversion.
Actually, only now I'm experimenting Diversion.

So, I tryed to "follow dnsmasq.log" with the "Unfiltered log" option and saw a huge amount of constant DNS querys for A and AAAA values for a specifc local host.

They all seem to come from the router itself. (from 127.0.0.1)
Code:
Feb  3 23:20:11 dnsmasq[16662]: query[A] [local_hostname] from 127.0.0.1
Feb  3 23:20:11 dnsmasq[16662]: query[A] [local_hostname] from 127.0.0.1
Feb  3 23:20:11 dnsmasq[16662]: /etc /hosts.dnsmasq [local_hostname] is 192.168.1.6
Feb  3 23:20:11 dnsmasq[16662]: /etc /hosts.dnsmasq [local_hostname] is 192.168.1.6
Feb  3 23:20:11 dnsmasq[16662]: query[AAAA] [local_hostname] from 127.0.0.1
Feb  3 23:20:11 dnsmasq[16662]: query[AAAA] [local_hostname] from 127.0.0.1
Feb  3 23:20:11 dnsmasq[16662]: config [local_hostname] is NODATA-IPv6
Feb  3 23:20:11 dnsmasq[16662]: config [local_hostname] is NODATA-IPv6

and sometimes from another host (from 192.168.1.5)
Code:
Feb  3 23:20:13 dnsmasq[16662]: query[A] [local_hostname] from 192.168.1.5
Feb  3 23:20:13 dnsmasq[16662]: query[A] [local_hostname] from 192.168.1.5
Feb  3 23:20:13 dnsmasq[16662]: /etc /hosts.dnsmasq [local_hostname] is 192.168.1.6
Feb  3 23:20:13 dnsmasq[16662]: /etc /hosts.dnsmasq [local_hostname] is 192.168.1.6
Feb  3 23:20:13 dnsmasq[16662]: query[AAAA] [local_hostname] from 192.168.1.5
Feb  3 23:20:13 dnsmasq[16662]: query[AAAA] [local_hostname] from 192.168.1.5
Feb  3 23:20:13 dnsmasq[16662]: config [local_hostname] is NODATA-IPv6
Feb  3 23:20:13 dnsmasq[16662]: config [local_hostname] is NODATA-IPv6

Also, after upgrading I got a high RAM usage out-of-the-box, possibly causing a 9ºC temperature increase.
I'm not sure what's that about and don't know if it is a Diversion issue or new firmware.

Above, I've added a <space> in between "/etc" and "/hosts.dnsmasq" to be able to post this tread, or else it would give me an error.

Any light?
 

L&LD

Part of the Furniture
Search for the RAM and temperature 'issues'. They aren't issues at all.

I don't think the logs are important at all either (just informational).
 

Markfree

Regular Contributor
It seems lots of people are experiencing this temperature rise after upgrading their router.

As for the logs, what I don't get is that it keeps growing quite fast.
Every second a bunch of "queries" show up, and mostly from 127.0.0.1.

When I turn down 192.168.1.6 the queries stop. So it seems to me there is something off about this specific host.
I'm still investigating though.
 

Markfree

Regular Contributor
I stopped my router's Zabbix agent and the queries stopped as well.
So I guess I found the culprit.

Now I need to find the reason for that behavior
 

Markfree

Regular Contributor
What I found so far is that Zabbix Agent queries DNS every time it sends data to the server if we set up "Server" or "ServerActive" parameter to a hostname/domain_name (which is what I did).

There is no DNS cache implemented at Zabbix and, according to this request, it seems there won't be any change in that behavior, despite years of discussion.

The only workaround I was able to infer is to use actual IP for "Server" option.
I guess that is a viable solution, but not an optimal one.

After setting up my agent to send data to the server with explicit IP 192.168.1.6, that huge amount of DNS queries stopped immediately.
Then I should do the same for every host with an agent configured. :rolleyes:

Another thing that bothered me is that Diversion was logging every single request dnsmasq received and filling up logs quite fast.
I disabled logging and right away lots of free memory.
graph.png


I guess it consumes lots of memory.
 

thelonelycoder

Part of the Furniture
Another thing that bothered me is that Diversion was logging every single request dnsmasq received and filling up logs quite fast.
I disabled logging and right away lots of free memory.
That’s what a log is for. To see what’s going on. Even if logging is disabled, these things happen anyway on the router, only hidden.
 

Markfree

Regular Contributor
Indeed it is. It sure helped me find those DNS queries.
But I could not find an option to reduce log levels. Is there one?
 

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top