RT-N66U with Merlin build DNS problem

[th0r]

Hi,

this is my first post and I registered because I have a problem.

3 weeks ago I bought RT-N66U and immediately updated it with Merlin build 774.39. I also installed Download master and connected an external disk. Everything worked perfect for 2 weeks.

Troubles began when my ISP provider briefly fell from the grid and the internet wasn't reachable. After and hour or so the internet was working, but only if you set DNS entries on the devices that were connected to RT-N66U. I set google DNS 8.8.8.8 and 8.8.4.4 for all my devices so the internet is working again.

I also noticed you can set the DNS settings in the router itself but there still was no internet connection if I didn't set DNS settings on the device itself.

I'm kinda lost, because I don't want to configure every visitor's device when someone comes to me. I updated to 774.40, but no luck.

Any advice?

Thanks guys.

 

[RMerlin]

Need more info on your ISP's type of connection. Is it PPPoe? DHCP?

Do you have the WAN page configured to automatically connect with the ISP's DNS?

 

[th0r]

Need more info on your ISP's type of connection. Is it PPPoe? DHCP?

Do you have the WAN page configured to automatically connect with the ISP's DNS?

My ISP's type of connection is PPPoE and yes now I have configured to connect with the ISP's DNS automatically. Just like it was before and it was working without problem.

 

[RMerlin]

My ISP's type of connection is PPPoE and yes now I have configured to connect with the ISP's DNS automatically. Just like it was before and it was working without problem.

Did you change anything related to DNS on the router's LAN -> DHCP Server page? Any customization done to dnsmasq's configuration? Are you running any security software on affected clients that might be rejecting the DNS?

Also check System Log to ensure your ISP is properly pushing their DNS to your router once the PPPoE session gets established.

 

[th0r]

Did you change anything related to DNS on the router's LAN -> DHCP Server page? Any customization done to dnsmasq's configuration? Are you running any security software on affected clients that might be rejecting the DNS?

Also check System Log to ensure your ISP is properly pushing their DNS to your router once the PPPoE session gets established.

I think I didn't but here's screenshot.

Sorry, but I don't know what to look in the log so I paste the whole one here.

 

[RMerlin]

I think I didn't but here's screenshot.

Sorry, but I don't know what to look in the log so I paste the whole one here.

I'm unable to do any lookup either using the two DNS your ISP is providing. Makes me wonder if their DNS are working properly.

Only solution I can see would be to configure the router to use your own DNS, on the WAN page.

 

[th0r]

I'm unable to do any lookup either using the two DNS your ISP is providing. Makes me wonder if their DNS are working properly.

Only solution I can see would be to configure the router to use your own DNS, on the WAN page.

I've restored to ASUS's official firmware and now my ISP's DNS that are set in WAN page automatically. Work without problem.

I'm sorry but there seems to be the problem with your FW although I liked it very much.

 

[Bongoberry]

Hi,

I've got the same problem with the merlin firmware - great firmware apart from the DNS issue. I've just upgraded to the latest release 374.40... If only I could recall what version I was on before hand ...

 

[colinbowern]

I'm unable to do any lookup either using the two DNS your ISP is providing. Makes me wonder if their DNS are working properly.

Only solution I can see would be to configure the router to use your own DNS, on the WAN page.

I hit the same problem today on an RT-AC66U running 374.42. I have a PPPoE connection. Work around is to use a public DNS service like OpenDNS or Level 3's DNS servers. When troubleshooting with my ISP they mentioned that they were seeing the router grab both an IP from DHCP and PPPoE on the WAN side. Not sure if that helps, but everything was working just fine up until 11am today when the ISP DNS servers stopped responding to ping, nslookup, etc. When I switch to a public DNS service and wait a bit I can then ping and nslookup them, but once I switch the router back to automatically using the WAN DNS servers it dies again.

 

[th0r]

After a while I updated my router again from stock to Merlin 374.42. Currently I don't have any problems. I did the full setup of a router from scratch. I hope that's that