Could not perform DNS name resolution

[JoshhDaw]

Hi I have the Zyxel 5G router from three & for the last 3-4 days I have been having issues with the network (it has been fine for the previous 8 months)

all 5 Nintendo Switches in the house won’t work and come up with error - Could not perform DNS name resolution.

All eufy (Anker) security cameras also not working. 

Every over device no issues though! 

I have tried everything from changing DNS to 8.8.8.8 / 8.8.4.4

resetting to factory & changing APN.

Three didn’t really seem to have a clue what they was on about and advised that they have ‘raised’ this and I will hear back within a week. Honestly I can’t wait a week with children wanting to play on their switches & having no security in the household!

thanks in advance. It’s driving me a little crazy haha

[Anvil_Iron]

Which firmware version is installed on the Zyxel router?

It could have been updated recently to version b14.

[JonathanB]

I wonder if this is similar cause as to the VPN issue you reported @Anvil_Iron?

@JoshhDaw there's more info on FYI : IPv6 Prevented VPN Connection but setting the APN to manual mode and using the 3internet APN with IPv4 only may help.

Thanks,
Jonathan

[JoshhDaw]

I did try this with no luck 😞 got them to replace the hub & sim but now 5G doesn’t work at all lol 

[Anvil_Iron]

Hi @JonathanB , it could well be. It's worth a try if DNSv6 server info is displayed in System Info.

[JoshhDaw]

Honestly having no luck! After souring the internet for most of the last 2 days and three saying it could take them several weeks to resolve I just ordered a new contract & got them to exempt my current one. 

Logic was they have no idea what’s going on so seemed my best chance of fixing! 

Since getting my router now having the error of 5G not working at all. Deffo not the sim card as I’ve tried the old one in the new router still with no luck. 

Three told me that there was no 5G in my area and then was speechless when I said the previous router was still running 5G fine and that I’d been using a previous router for 8 months 😂

[Anvil_Iron]

Is your replacement router still a Zyxel NR5103E?

What firmware version does it have?

After a factory reset, does the router display both DNSv4 and DNSv6 addresses or just DNSv4 addresses on the System Info page?

[samuelcooper96]

I could also do with finding a solution. All devices except my Nintendo Switch connect through to the internet fine with my NR5103E router. I've tried resetting Nintendo Switch, router, trying public DNS such as Google's and Cloudflare's, tried entering DNS manually on Nintendo Switch, all to no avail.

So something must be happening on Three's network?

[GregBlanks]

I have gone through this same issues started on wed/thurs all my camera not connecting . After playing in the router settings I found a fix , go into router settings and into remote management and under WAN enable HTTP HTTPS and SSH click apply . this fixed my camera allowing them to reconnect etc . hope this helps 

[samuelcooper96]

I have done exactly this and still my Nintendo Switch does not connect for some reason. I’m not sure what else there is to do