Upgraded a 2830 to a 2866 about 6 months ago. Set the 2866 up from scratch and generally all seemed ok, but every once in a while the router seemed to lock up. I lost internet access and pinging the routers ip timed out. After a reboot all came back up ok. Think I was on firmware version 4.3.2.1_BT.

Noticed in firmware 4.4.1_BT that it mentioned "Improved memory management mechanisms", so I upgraded to that a few weeks ago. Now, still monitoring whether it has stopped the lockups (not sure I have had one since), but I have had the router reboot on me at least once.

However, since the upgrade the Applications - LAN DNS doesn't seem to be working as it was before. This is a home setup, and I run a few services that are visible from the internet, so for local resolution I have set up some LAN DNS entries with the external DNS name pointing at the internal IP. This worked fine before the firmware upgrade, but not now.

If my clients are pointed at my internal DNS server (which then uses root hints) it isn't resolving to the local address, however if I point a client at the IP of the router for DNS then it does. Now, this may be expected behaviour, but I thought LAN DNS intercepted ALL DNS requests going through the router (not just requests directed at it) and it used to work ok, but has stopped working since the firmware upgrade.

Anyone else experiencing the same LAN DNS issues (or even lockup / reboot issues).

Anyone else experiencing the same LAN DNS issues (or even lockup / reboot issues).

I don't know if it's related but I'm having a few DNS issues with my new Draytek Vigor 2866ac. I'm on the latest firmware 4.4.1_BT

Background: I'm with Zen internet and previously had a BT Openreach modem with an Asus RT-AC88U router and a mixed bag of APs. I decided to rationalise and tidy up. I got a the 2866ac and two VigorAP903 and formed a mesh network. This is a home setup. It works quite nicely.

But, I started noticing timeouts connecting to my mail server. I'm with Mythic Beasts for mail hosting and I started to notice erratic response when either ssh'ing or retrieving mail. After a bit of experimenting I discovered that often, but not always, the DNS was not resolving correctly. I've always left the router settings untouched and it defaults to Zen's own DNS resolvers.e.g. The mailhost and ssh server is lynx.mythic-beasts.com and it should resolve to 93.93.131.3 but sometimes it resolves to 42.0.16.152,
I have a home lan of mostly Linux PCs (debian), raspberry pis and Apple macs and mobile devices. Router is 192.168.1.1 and clients have DNS set to router address. Same setup I've always had with routers and defaulted to Zen's DNS.

e.g: on one of my Linux PCs with the DNS temporarily set to Cloudflare:

Code:

dougie@office:~$ nslookup lynx.mythic-beasts.com Server: 1.1.1.1 Address: 1.1.1.1#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 42.0.16.152 Name: lynx.mythic-beasts.com Address: 93.93.131.3 ...

whois shows 42.0.16.152 to be

Code:

netname: CHINANET-GD descr: CHINANET Guangdong province network

Everyday's a schoolday and I've been reading about DNS hijacking and wondering if this is an example.

I've been experimenting with different DNS resolvers and tried Quad9 and Cloudflare. The router status page confirms these changes but nslookups are still pretty inconsistent and the chinanet address is usually in there somewhere.

Out of curiousity I reverted back to my Asus RT-AC88U with the BT Openreach modem and all is ok again. Chinanet has gone. I thought I'd try pluging the Draytek router into the Openreach modem via one of the RJ45 ports but I couldn't get it to work. It only seems to work with a direct connection from the DSL port.

To summarise:
1. Problem only happens with Draytek.
2. Changing DNS resolvers has no consistent/reproducable effect.

The other point of interest is that I have an expressVPN subscription. I don't normally have it on but I can enable it at the client level. The instant I do this the problem disappears. So presumably whatever DNS resolvers the expressVPN server uses are fine.

I have a very basic setup and don't use (or understand) any of the sophisticated options the Draytek offers. I've been struggling with this for a few days and I'm out of ideas.

Very strainge, on my pc (Win 10) pointed at my internal DNS server (that uses root hints) this is what I get:

Code:

C:\Users\Ian>nslookup lynx.mythic-beasts.com Server: UnKnown Address: 192.168.0.201 Non-authoritative answer: Name: lynx.mythic-beasts.com Addresses: 2a00:1098:0:86:1000::33 93.93.131.3

However when I changed the pc to use the routers IP as DNS I get:

Code:

C:\Users\Ian>nslookup lynx.mythic-beasts.com Server: UnKnown Address: 192.168.0.1 Non-authoritative answer: Name: lynx.mythic-beasts.com Addresses: 5d5d:8303:: 2a00:1098:0:86:1000::33 93.93.131.3 42.0.16.152

And changing it to Googles DNS:

Code:

C:\Users\Ian>nslookup lynx.mythic-beasts.com Server: dns.google Address: 8.8.8.8 Non-authoritative answer: Name: lynx.mythic-beasts.com Addresses: 5d5d:8303:: 2a00:1098:0:86:1000::33 93.93.131.3 42.0.16.152

Doing a look up at mxtoolbox.com just returns the 93.93.131.3 address.

Seeing as when I use my internal DNS the router doesn't seem to intercept the requests (as per my problem / issue) it does seem that it may be the router adding the 42.0.16.152 when pointed at it (or an external DNS). Do you have anything configured under: Applications - LAN DNS. I do, but nothing for 42.0.16.152

Seeing as when I use my internal DNS the router doesn't seem to intercept the requests (as per my problem / issue) it does seem that it may be the router adding the 42.0.16.152 when pointed at it (or an external DNS). Do you have anything configured under: Applications - LAN DNS. I do, but nothing for 42.0.16.152

That's interesting. Not just me then. I have nothing configured under Applications - LAN DNS - and have tried to keep the setup as simple as possible. Which makes it all the more frustrating. I'm going to try a factory reset of the router and start over. Also I believe it should be possible to use the router with a modem so I'm going to give that a try.

The fact that plugging my old setup back in (Asus router with BT Openreach modem) does not present these issues does rather point at the Draytek being implicated. I've been browsing some of the (mostly quite old now) posts about Draytek vulnerabilities but my firmware is up to date, and I've tried using older firmware.

The results/confirmation after a few more experiments.
1. Swapping old ASUS router back in and problem disappears.
2. Activating expressVPN and problem disappears.
3. Cannot get Draytek to work with BT Openreach modem on WAN2 despite documentation clearly saying it's possible and process quite straightforward.

I did consider trying to bring back my ASUS router as a router only then set up my 2866 as a Mesh root only but this feels really clunky and inelegant and defeats the point of trying to tidy up my setup.

Code:

# # Connected using ASUS RT-AC88U and BT Openreach modem # # # DNS manually configured on Linux client to use 9.9.9.9 # dougie@office:~$ nslookup lynx.mythic-beasts.com Server: 9.9.9.9 Address: 9.9.9.9#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 93.93.131.3 Name: lynx.mythic-beasts.com Address: 2a00:1098:0:86:1000::33 # # Connected using Draytek 2866ac # dougie@office:~$ date Thu 10 Nov 16:19:20 GMT 2022 dougie@office:~$ nslookup lynx.mythic-beasts.com Server: 9.9.9.9 Address: 9.9.9.9#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 93.93.131.3 Name: lynx.mythic-beasts.com Address: 42.0.16.152 Name: lynx.mythic-beasts.com Address: 5d5d:8303:: Name: lynx.mythic-beasts.com Address: 2a00:1098:0:86:1000::33 # # nslookups on another Linux client using default DNS # (Zen's DNS servers) # # # BT Openreach modem and ASUS RS-AC88U # dougie@macoffice:~$ nslookup lynx.mythic-beasts.com Server: 192.168.1.1 Address: 192.168.1.1#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 93.93.131.3 Name: lynx.mythic-beasts.com Address: 2a00:1098:0:86:1000::33 # # Draytek 2866ac # dougie@macoffice:~$ nslookup lynx.mythic-beasts.com Server: 192.168.1.1 Address: 192.168.1.1#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 93.93.131.3 Name: lynx.mythic-beasts.com Address: 42.0.16.152 Name: lynx.mythic-beasts.com Address: 5d5d:8303:: Name: lynx.mythic-beasts.com Address: 2a00:1098:0:86:1000::33 # # With expressvpn active # dougie@office:~$ nslookup lynx.mythic-beasts.com Server: 100.64.100.1 Address: 100.64.100.1#53 Non-authoritative answer: Name: lynx.mythic-beasts.com Address: 93.93.131.3