Interesting... Dahua T5442T-ZE with blank DNS settings still attempts to find Google DNS servers

[Mike A.]

While using Wireshark today for another reason, I noticed that one of my 5442T-ZE cams appears to send ARP request in an attempt to find Google's DNS servers even though I have DNS entries on the cam set to 0.0.0.0 for both primary and secondary DNS servers (see image below). Nothing else in the cam setup pointing to Google. Changing the DNS entries to the IP address of the cam appears to stop this. Cam is blocked so can't do much with it but thought that the behavior was interesting. Firmware on this cam is V2.800.15OG004.0.R, Build Date: 2020-10-19.

 

[Flintstone61]

Very Interesting. Is your router setup with Google DNS populated in the boxes?
I set up a few Dahua's recently, 1 was the 6mm flavor of 5442 turret. The only change I made under network was to turn off dhcp and enable static and give it a new address.
checking thru a few things yesterday, I saw one of the new cams with a 8.8.4.4 and the local 192.168.1.1 hmmm maybe it was the whole NVR.....I'm not nearby the machine.....
gonna poke around tomorrow......

 

[Mike A.]

No. I don't use Google's DNS servers or have anything else pointed there. IP address for the cam is static and gateway is set to the cam itself so it shouldn't pull anything from my router. Must be hard coded into the firmware.

 

[sebastiantombs]

Try using x.x.x.254 for the gateway. Replace the x with your normal IP scheme. I use that trick along with 0.0.0.0 for a gateway on all my cameras and never had a problem.

 

[Mike A.]

Yeah, .254 or cam's IP will work. As above, it stops looking after changing to the DNS to the cam's own IP. Some cams won't take 0.0.0.0 for gateway so I'll usually just use the cam's IP now.

I've used 0.0.0.0 for both gateway and DNS servers on various other cams and thought both would work. Apparently when this one sees that it tries to find Google's DNS servers on its own. I don't see any other Dahua cams doing the same even those that I had with 0.0.0.0 for the DNS.