DNS error - who is the culprit? (solved)

[Perene]

I bought a new gigabit router, Archer C8, using the v2 firmware, and last version.

The router so far didn't present any conectivity issues using wifi, and surpassed the old non-gigabit DIR-809 I had.

It came with a CAT5-E cable. So I used this cable to connect to the ISP modem. Then I did the following:

- Already had a CAT-6 ethernet cable here, but had to cut the cable and insert new connectors.

In other words, the CAT-6 wasn't already available for me to use it, and I asked a person to do this job. Then I tested for a few days. The CAT-6 connected in my PC and from there to the Archer C8 LAN port. I also updated the Realtek drivers.

3 times I had this problem: in the PC the browser stopped working, saying DNS Error, not connected... and this has always happened when I had JDownloader and Vuze (torrent software) downloading things (using the max DL speed from my ISP). I noticed everytime this happened the downloads weren't stopped, they continued, and the wifi was still working.

Someone said to me that working on the cable wasn't desirable, that I should have prefered an ethernet cable (CAT 5-E or 6) that was already finished, with its connectors in place.

I am beginning to think that these DNS errors (that are gone after seconds or when we reboot the devices) are related to this. I am going to purchase a new CAT 5-E cable, however I need to ask you if DNS_PROBE_FINISHED_NO_INTERNET can be related to a defective ethernet cable.

So far I am not considering this might be Archer C8's fault.

 

[Perene]

I discovered something important: replacing the cable still gives me the issue. However, when I told Windows 10 Pro-64 bit to fix it, it enabled "DHCP for ethernet", reverting these settings below for an automatic IP:

However, I had to configure this way AGAIN because if I don't tell this router that my PC needs to use 192.168.8.100, then I won't have the port forwarded to 7001, so I won't be able to use UTorrent with the port 7001 forwarded.

I noticed the DNS error right after I restarted Windows. That tells me that there's a conflict between my PC and the router, meaning the PC tries to use 192.168.8.100, the router somehow doesn't understand that and this gives me a DNS error while using Chrome browser.

I also checked and the wifi connection remained 100% OK while the error presented itself.

That begs the question: what could be causing this issue? Is it the router or the PC and its network card? Or maybe I need to change some setting in the Archer C8 to make the IP 192.168.8.100 fixed for a specific MAC, from this PC?

If what I wrote before is needed, it would be the first time I have to do this.

Another theory: the initial DHCP IP address from the Archer (gateway 192.168.8.1) is 192.168.8.100 (end IP is 192.168.8.199). Maybe this means the conflict happens because other devices (using wifi and with automatic IP settings) could be using the same IP address.

I'll change it to 192.168.8.143 to see if this helps.

 

[gbeirn]

Did you take that picture or is from the Internet somewhere? The brown and brown/white wires are reversed

 

[Perene]

This problem has been solved with the use of the setting: DHCP > Address Reservation from the Archer C8. I configured with the MAC of my PC, and set the IP to have a permanent lease time, for 192.168.8.144. The current gateway from the router is 192.168.8.1, and the DHCP for it starts with 192.168.8.100 and ends with 192.168.8.199. Most definitely this was a conflict. The PC tried to use an IP address (192.168.8.100) that was already in use.