Tp-link router DNS issue

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In my home I have an internet connection in the wall (female) from where my internet is provided. A couple of months ago I used a D-link router to spread the internet in the home. Sadly they D-link router died. Anyways I bought a tp-link router and plugged it in and everything was working fine the first week. Then after a week I got different DNS problems.

  • Dns probe finished no internet
  • Dns server not responding

I tried to reset router, change dns settings in Windows to googles (8.8.8.8, 8.8.4.4), flush dns from cmd, change dns server inside of the routers setting, none of which have worked. If I face a dns problem, then rebooting the router, I will have internet acces for around 1h, then the problems will accour again. By experience it seems that when i go to netflix it will often dropp internet access. Like netflix is some kind of "trigger". When I put an ethernet cable directly from the wall to computer, internet works fine. So by my conclusion there is something wrong with the router.

The model number is TL-WR840N/TL-WR840ND

I have tried to explain as best as I can, but I have very low (none) experience in this field.

Edit 1: an answer to Alexs question

From wall to computer Ethernet adapter Ethernet:

  • Connection-specific DNS Suffix . :

  • Link-local IPv6 Address . . . . . : fe80::e568:d749:2132:a65a%6

  • IPv4 Address. . . . . . . . . . . : 192.168.138.23

  • Subnet Mask . . . . . . . . . . . : 255.255.255.0

  • Default Gateway . . . . . . . . . : 192.168.138.1

From wall to router, router to computer Ethernet adapter Ethernet:

  • Connection-specific DNS Suffix . :

  • Link-local IPv6 Address . . . . . : fe80::e568:d749:2132:a65a%6

  • IPv4 Address. . . . . . . . . . . : 192.168.0.102

  • Subnet Mask . . . . . . . . . . . : 255.255.255.0

  • Default Gateway . . . . . . . . . : 192.168.0.1

From wall to router, then wifi Wireless LAN adapter Wi-Fi:

  • Connection-specific DNS Suffix . :

  • Link-local IPv6 Address . . . . . : fe80::cc96:5a79:ea35:7b0%14

  • IPv4 Address. . . . . . . . . . . : 192.168.0.101

  • Subnet Mask . . . . . . . . . . . : 255.255.255.0

  • Default Gateway . . . . . . . . . : 192.168.0.1

Edit 2: I live in a studenthouse who uses something called mikrotik OS http://www.mikrotik.com/ I must every 10h sign in to this "OS" with my room number and some random password.

Olba12

Posted 2017-01-23T20:31:28.110

Reputation: 23

Google's DNS 8.8.8.4 is wrong, correct one 8.8.4.4. When you plug computer directly to the wall, what ip address you get(use ipconfig from cmd to get it) and what IP would be assigned when you connecting via your router? – Alex – 2017-01-23T23:12:44.283

I decided to edit my question for read ability. And yes I agree it is 8.8.4.4, just an error in the original post. @Alex – Olba12 – 2017-01-24T19:10:36.167

Does provider of this 192.168.138.0/24 network allow to use own routers? It could be on their side. Try to change MAC address on WAN side to the same as yours computer(there should be a button that says something - "copy my MAC" similar to this)

– Alex – 2017-01-25T04:50:57.203

I dony know actually, I do not want to ask them. But it's not in the roomagreement or house rules. Hmm, I can try to clone the mac adress sure. The weird thing though is that yeasterday night i turned off my computer and started the router. I has now worked for 10 hours, I have been connected with my smartphone the whole time and nothing else. 10 hours is considered a long time, given how it has worked the last days. @Alex – Olba12 – 2017-01-25T09:19:05.147

When I connected my computer to the router, the internet went off 5 minutes after "dns probe finished no internet" in chrome. @Alex – Olba12 – 2017-01-25T09:45:14.920

Consumer grade routers are limited in trem of memory so they can't hold huge tables of current connections. If there is torrents, stop them, also if it Win10 change setting how updates delivered(by default M$ share your computer with others). Shut off news, stocks, weather and other backgrounds. Run tcpview as admin to spot which program abuse network

– Alex – 2017-01-25T17:02:39.640

I'm actaully flashing my SSD and reinstalling Windows right now. Funny thing is that, during the setup it asked for internet and I choosed my router. Got dc:ed again... I will try tcpview when I can. But I dont understand, had no problem with old router. @Alex – Olba12 – 2017-01-25T17:11:58.117

I tested many consumer's router (by placing them behind decent unix firewall) and found that some of them (if not all) really like to call home in assumption that device set as a first router that facing internet. Some of them due to its short vision that device can be firewalled or set in private range of IP get stuck. If you would have a choice to know DHCP IP range assigned in 192.168.138.0/24 we could try to setup static IP on the WAN side but since it behind of your control there is chance we can step on IP already assigned. – Alex – 2017-01-25T18:14:39.650

If your provider allowing multiple devices from the same room, you may setup your WiFi router in access point mode but we still need some static IP from 192.168.138.0/24 to be able to do that. This way DNS issues will be eliminated and router itself will serve a single function - to connect wirelessly to the current network – Alex – 2017-01-25T18:19:47.023

Yes it's very likely that there is a router which my router connects to. But I do not know how to get the static ip from 192.168.138.0/24. How would you suggest that I proceed? @Alex – Olba12 – 2017-01-25T19:01:25.903

I can still not wrap my head around why it works when I'm connected through phone and not computer. @Alex – Olba12 – 2017-01-26T00:44:15.243

Check version of firmware on your router and if it is lower than latest on official site then try to upgrade to new firmware (Make sure you choose right download since firmware for V1 and V2 incompatible )

– Alex – 2017-01-26T04:52:33.270

I have tried the following since my last comment. 1) Updated my drivers on network card on computer, no succés. 2) Booted on UBUNTU from usb, no succés, updated firmware on router, now nothing works, not even the phone. @Alex – Olba12 – 2017-01-26T21:16:32.597

Maybe I have just connected my router in a wrongful way to the mikrotek os thing? – Olba12 – 2017-01-26T22:43:26.453

I don't think you connect it wrong, WAN port should just go to the wall socket and settings of WAN port set to DHCP. Than more we trying than more I think it is an issue on provider's side. IMHO the best solution would be to visit IT who managing that mikrotik firewall and ask them to add your router in exclusion list since they doing HotSpot time base filtering. You can try one more solution - use your router as access point. Set IP on LAN(!!!) port (router) as 192.168.138.254/255.255.255.0 and disable DHCP then plug your router as LAN port -> Wall and leave WAN port open. – Alex – 2017-01-27T08:25:03.530

One manipulation that sometimes helps is to turn off IPv6 in router and computer, as perhaps mikrotik does not support it very well. Have you tried with other routers? If nothing works, I suggest getting in touch with the mikrotik administrator as the problem might be some setting on his side. – harrymc – 2017-01-27T10:02:52.243

The point access works, no dns problems, works great on phone, on computer it's not stable. It sometimes just "drops" the internet access, even though it works fine on the phone. @alex – Olba12 – 2017-01-28T11:38:15.267

Yeah, finally we won this stubborn TP-Link... but to be correct it is mikrotik. I moved part of comment regarding access point to the answer – Alex – 2017-01-28T19:07:08.330

Answers

1

IMHO the best solution would be to visit IT who managing that mikrotik firewall and ask them to add your router in exclusion list since they doing some kind of HotSpot time base filtering.

You can try one more solution - use your router as access point. Set IP on LAN(!!!) port (router) as 192.168.138.254/255.255.255.0 and disable DHCP then plug your router as LAN port <-> Wall and leave WAN port open.

Just keep in mind that it blindly chosen static IP (192.168.138.254) in hope it wouldn't seat in DHCP range of mikrotik.

Alex

Posted 2017-01-23T20:31:28.110

Reputation: 5 606

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Ideally you should set your TL-WR840N to bridge/AP mode and your PC's IP settings to DHCP (including DNS servers), this way your PC can pick up the settings assigned by the Miktotik router.

If not, when the Mikrotik Captive Portal kicks in you might not be able to connect to it's web page (for entering the room_no/passwd) as you might be on the wrong IP subnet. That in turn will cut off all internet access for you.

Mikrotik can be setup to restrict your access to remote DNS servers even when you are logged in. This restriction is definitely active when you are in captive portal mode (i.e. you have to enter the password). So ideally your DNS server should be the Mikrotik.

You can see the subnet used by Mikrotik LAN DHCP server by connecting your PC (in DHCP mode) directly to the wall plug and once the internet works run cmd.exe and type ipconfig in the terminal.

Typically Mikrotiks are set to do bandwidth shaping as well i.e. to automatically throttle your speed if you exceed a predefined threshold of downloaded MB/GB in a period of time (like if you download a lot of video). This is to prevent one user hogging up all the bandwidth.

If the Mikrotik is configured correctly it is impossible to bypass its rules and filters even with a spoofed MAC ;)

If all of the above doesn't work then your TL-WR840N is broken.

Chris S.

Posted 2017-01-23T20:31:28.110

Reputation: 1

How do I set my PC:s settings to dhcp? Today I have been able to, connect pc via router that is in AP mode. But on phone I cant get pass the log in window. It just refuses to give me access. – Olba12 – 2017-01-31T03:02:13.470

Ok I google it, and both ip/dns is set to automatically in Windows. – Olba12 – 2017-01-31T03:07:39.400

Asked: 2017-01-23T20:31:28.110

Viewed: 2 155 times

Active: 2019-01-23T14:58:23.277