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Router not resolving some DNS until rebooted

fourmiles
2: Seeker
2: Seeker

I had set Cloudflare 1.1.1.1 and 1.0.0.1 as my primary and secondary DNS in my Vodafone router (I'm a Gigafast customer in Milton Keynes).

 

Yesterday I stopped being able to reach some websites, but not all. For example, bbc.co.uk was down, as was Epic Megagames. I could not ping or tracert to either of these.

 

I rebooted the router, and access to these came back fine, but 24 hours later the same has happened. Again, I rebooted the router and access to these is resolved.

 

I have now changed the router settings to Google DNS 8.8.8.8 and OpenDNS 208.67.222.222 to see if this persists, but can anyone suggest why the router would suddenly stop resolving some addresses, but not all, but that a reboot clears this?

 

I have had no real issues in over 2 years.

6 REPLIES 6

Anonymous
Not applicable

I'll get criticized for oversimplifying but here goes:

 

DNS servers return IP addresses based on easy text addresses that are submitted to them.  The IP address your device grabs from the DNS server is then presented to routing servers to create a path between your device and the target IP address.

 

I doubt that the DNS servers you are using are suddenly presenting your devices with incorrect IP address targets.  That a VF/CityFibre routing server could be doing something stupid (from a short list of possibilities), is far more probable!

 

A useful little command in Windows is "pathping", which not only performs a trace-route (tracert) but also gives the delay to each server on the route:  *100% loss does not necessarily mean there is a fault, intermediate servers can and often are set up not to respond to pings!

 

PS C:\Users\keith> pathping bbc.co.uk

Tracing route to bbc.co.uk [151.101.0.81]
over a maximum of 30 hops:
0 KeithsLaptop.local [192.168.127.222]
1 router.local [192.168.127.1]
2 host-212-158-250-39.dslgb.com [212.158.250.39]
3 63.130.105.110
4 90.255.251.117
5 151.101.0.81

Computing statistics for 125 seconds...
Source to Here This Node/Link
Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address
0 KeithsLaptop.local [192.168.127.222]
0/ 100 = 0% |
1 1ms 0/ 100 = 0% 0/ 100 = 0% router.local [192.168.127.1]
0/ 100 = 0% |
2 11ms 0/ 100 = 0% 0/ 100 = 0% host-212-158-250-39.dslgb.com [212.158.250.39]
0/ 100 = 0% |
3 --- 100/ 100 =100% 100/ 100 =100% 63.130.105.110
0/ 100 = 0% |
4 --- 100/ 100 =100% 100/ 100 =100% 90.255.251.117
0/ 100 = 0% |
5 10ms 0/ 100 = 0% 0/ 100 = 0% 151.101.0.81

Trace complete.

 

gipjon
16: Advanced member
16: Advanced member

Did changing the DNS work . 

So, the same has happened this afternoon - this time I can get to bbc.co.uk fine, but Microsoft Windows Update will not connect - reporting that it cannot connect to the Windows Update server.

 

Again, a reboot of the router clears this error, and it will resolve and connect.

 

This time I have performed a Factory Reset of the router and set Quad9 and OpenDNS as the DNS servers, and will see how I get on. The factory reset has rolled the firmware back from 19.4.0551-3269083 to 19.2.0307-3261020

Jayach
16: Advanced member
16: Advanced member

@fourmiles wrote:

This time I have performed a Factory Reset of the router and set Quad9 and OpenDNS as the DNS servers, and will see how I get on. The factory reset has rolled the firmware back from 19.4.0551-3269083 to 19.2.0307-3261020


I'm betting that may cure it. I haven't heard of anyone on 19.4.0551-3269083 and it is strange for firmware to be rolled back unless there is a known problem with it.

Fingers crossed🤞

Just out of curiosity, how would I have ended up on a later firmware that nobody else has heard of? There are certainly no Google search results for 19.4.0551 so what has happened to give me a firmware that nobody else has? As I hard reset the device I can't see the logs so I have no idea if this was a recent update. Certainly it was not anything I did! 

 

I can see from some other websites that people are reporting 19.4.0539 released on 10th March for other Technicolor devices, but not for Vodafone.

gipjon
16: Advanced member
16: Advanced member

Very odd .unless it the pro firmware that makes the wi-fi extended work.

Don't reboot your router to offered in a short time . You may trigger the line management to think there is a line fault and slow your connection down