OpenWrt - LuCI: Lot of Reverse DNS lookups

I've installed OpenWrt (18.06.2) on my new TP-Link Archer C7 v5 (EU).
Installation was easy and it seems to run good.

There is a strange behavior when I'm logged in in LuCI Web Interface with "AUTO REFRESH ON": There are a lot of reverse DNS lookups for private IP addresses at my Pi-hole server and a lot of open UDP connections on port 53 at OpenWrt.

These rDNS resolutions, every 5 seconds, fill my log at the Pi-hole. It's not a kind of not-working but it's a kind of not-nice.
It would be fine, if these rDNS could be stopped.
If I switch off "AUTO REFRESH" there are no reverse DNS requests from OpenWrt.
Note: The rDNS resolutions are not on every screen on LuCI but for example on the screen "Overview" Screen (Menu "Status") or at "Realtime Graphs".

I guess, it's not good/okay to have reverse DNS lookups every five seconds.

My setup:

  • Gateway/Router (VDSL)
    • Switch
    • OpenWrt (as access point: firewall, dnsmasq and odhcpd are disabled)
    • Pi-hole (with unbound)
    • static IP addresses: (PC, HTPC
    • Smartphone (dyn. IP, currently form the gateway access point)

My only DHCP server is the Pi-hole. DHCP server at the gateway (router) and the WLAN router are deactivated.
Note: I have to use the Pi-hole as DHCP server, because I cannot change the DNS-server at my router.

@NeroNero, welcome to the community!

If you are looking at the Connection Status page when this occurs, that is normal. LuCI looks up the reverse record of all IPs listed.

1 Like

BTW: I was blocked from the forum, just because I tried to add more than one picture in my initial post.
I was also not possible to write to a generic/group account.
I hate this forum software.

However, even if it's normal, I don't like it.
It's also not possible to deactivate "AUTO REFRESH" permanently. After every activity in LuCI Auto Refresh is active again. :frowning:

Odd, never seen someone "blocked." I have seen posting restricted for 24 hours or so. Are you saying that you've been "blocked" 19 days?

Also, be mindful the pic you posted is not OpenWrt.

Perhaps you should make a new thread for this issue. I'm quite curious to learn why this is an problem in your use case. Also, it doesn't occur on every LuCI activity, only when a page that uses it is refreshed - or you browse to a new page including it. For example, if you don't want the Connections page to (continuously) do DNS lookups, just hit the button. It'll stay that way until you refresh.

I was not able to replay and not able to create a new topic.

It's the result of OpenWrt, so what?
I couldn't post other related screenshots for OpenWrt because I've been blocked as I've tried to post more than one picture.

Why a new thread? This is the thread for this behavior, I'm not happy with.
My "problem" ("... it's a kind of not-nice") is written in my initial post: "a lot of reverse DNS lookups for private IP addresses at my Pi-hole server and a lot of open UDP connections on port 53 at OpenWrt" that "fill my log at the Pi-hole". And all the open UDP connections are IMHO (for me) unnecessary load on the router (and also on my Pi-hole server).
And it occurs on nearly every activity in LuCI, because almost every activity causes a reload.

Here the other screenshots, I'd like to add in my initial posting.

You're describing normal behavior.

  • It's normal behavior, are you saying that you do not want OpenWrt to look up IPs during netstat?
  • Why don't you turn of DNS rebind on the pihole then?
  • You can also use another DNS server (you won't get local lookups though, which it seems you don't desire to have)
  • You may be able to alter that behavior in code - but since you don't want to start a new thread, consider moving this one to the For Developers section to get more traffic from those who could help in that endeavor