topic Re: DNS problems with Technicolor TG582n in My Router

DNS problems with Technicolor TG582n

gothick — Fri, 23 Jun 2023 17:49:11 GMT

I've had my TG582n since I started with Plusnet some years ago and it's generally been very reliable. In the last week, however, I've been seeing odd problems where my connection to the internet is fine (and devices that are configured to use OpenDNS's servers rather than asking the router continue to work perfectly) but DNS lookups fail. They continue to fail until I reboot the router, at which point everything is fine for about half a day, and then things get screwy again.

When I investigated a couple of days ago I found that the router was returning 192.18.* addresses instead of the real DNS results e.g.:

> ;; ANSWER SECTION:

> twitter.com. 0 IN A 198.18.1.3

Doing a search of the forum, I figured I'd turn off WANDownSpoofing, but having done that I'm finding that DNS lookups at the router just timeout instead:

matt@Matts-iMac ~> dig A twitter.com @192.168.1.254 9 ; <<>> DiG 9.10.6 <<>> A twitter.com @192.168.1.254 ;; global options: +cmd ;; connection timed out; no servers could be reached

However, the rest of the internet is working, I can look up results just fine on the router's configured DNS servers (e.g. the same query against 212.159.13.52 works fine.)

My network is currently in this state as I type, but my Mac is unaffected because it's using OpenDNS and my Fire TV is streaming video just fine. However, devices using the default DNS config from the router, like my Blink Camera, iPhone and iPad are toast.

If I reboot the router right now, everything will be fine for a while but at some point in the next twelve hours-ish, I'll be back with it broken again.

Any hints?

Thanks!

Matt

Re: DNS problems with Technicolor TG582n

dvorak — Fri, 23 Jun 2023 20:04:36 GMT

Moderators Note

This topic has been moved from Broadband to My Router

Re: DNS problems with Technicolor TG582n

RPMozley — Fri, 23 Jun 2023 21:42:03 GMT

With the Technicolor you can set OpenDNS on the router. It’s done by a few commands via telnet. I can’t remember the exact commands right now, will look them up later. (@npr had a website with details on this a long while back, should still be accessible via the wayback machine @ archive.org)

Changing the DNS servers on the router might clear your issue or it might not but can’t hurt to try.

Re: DNS problems with Technicolor TG582n

RPMozley — Fri, 23 Jun 2023 22:09:04 GMT

Found the page on the wayback machine. Here:
https://web.archive.org/web/20160802034809/http://npr.me.uk/changedns.html

Re: DNS problems with Technicolor TG582n

MisterW — Sat, 24 Jun 2023 05:02:41 GMT

This sounds like the old wandownspoofing problem here https://community.plus.net/t5/Broadband/DNS-problems-with-Technicolor-TG582n/td-p/1181838

Re: DNS problems with Technicolor TG582n

gothick — Sat, 24 Jun 2023 09:38:47 GMT

@RPMozley wrote:
With the Technicolor you can set OpenDNS on the router. It’s done by a few commands via telnet. I can’t remember the
Changing the DNS servers on the router might clear your issue or it might not but can’t hurt to try.

I think that may be worth trying, especially as I've done more investigation and found that when the problem happens, the router seems to have completely forgotten that it knows about the Plusnet nameservers (after a reboot, "dns server forward list" shows 212.159.13.51 and 212.159.13.52, but when the problem happens it shows no forwarded nameservers at all.)

Next time the problem shows up, I'll try setting the router's nameservers to the OpenDNS ones.

I wonder what would cause the router to suddenly forget about the Plusnet nameservers, especially without any interruption in service?

Re: DNS problems with Technicolor TG582n

gothick — Sat, 24 Jun 2023 09:39:05 GMT

@MisterW wrote:

This sounds like the old wandownspoofing problem here https://community.plus.net/t5/Broadband/DNS-problems-with-Technicolor-TG582n/td-p/1181838

As I said in my post, I've turned off spoofing. While it was spoofing in the first place, turning off spoofing has simply shown up the underlying problem that the router seems to be randomly forgetting the list of Plusnet nameservers that it's meant to be forwarding requests to.

Re: DNS problems with Technicolor TG582n

MisterW — Sat, 24 Jun 2023 10:07:54 GMT

@gothick if youve recontracted in the recent past , I'd suggest you ask for one of the latest routers. The TG582 is VERY long in the tooth and will not have had any updates for a LONG time. You should be able to get one for the P & P cost of £6.99