How do I stop my Vodafone router giving a .broadband DNS suffix?

Quartz · 10 Dec 2022 at 12:31

My THG3000 Vodafone router gives DHCP clients a .broadband suffix for DNS. This is causing some issues, and it's preventing Windows 11 clients connecting to my server and NAS.

So how do I fix it? As it handles my wifi I cannot just roll up a DHCP server. I cannot see any way to change the DHCP options in the router's configuration.

I was looking at replacing it with a Draytek router but that didn't work out.

Caged · 10 Dec 2022 at 12:53

There's no reason why the DHCP server has to be the gateway, if you have a device like a Pi then you could use that as your DHCP server. If you still have the Draytek router there's no reason why that won't work with Vodafone.

Quartz · 10 Dec 2022 at 13:24

Caged said:
If you still have the Draytek router there's no reason why that won't work with Vodafone.

I used to double-NAT when I was with BT and while it worked, it proved an embuggeration in the end. Or do you mean that I disable DHCP etc on the Vodafone router then plug it into the switch side of the Draytek?

ChrisD. · 10 Dec 2022 at 14:44

Quartz said:
I used to double-NAT when I was with BT and while it worked, it proved an embuggeration in the end. Or do you mean that I disable DHCP etc on the Vodafone router then plug it into the switch side of the Draytek?

He means just replace the Vodafone router and use your own.

Quartz · 10 Dec 2022 at 14:53

ChrisD. said:
He means just replace the Vodafone router and use your own.

Sadly not possible.

ChrisD. · 10 Dec 2022 at 14:54

Quartz said:
Sadly not possible.

Why not?

Quartz · 10 Dec 2022 at 14:55

ChrisD. said:
Why not?

Because it also provides my land line.

Rainmaker · 11 Dec 2022 at 21:08

Disable DHCP on the Voda router, and run dhcpd or (better yet) AdGuard Home on a Pi or similar. Set the latter to be DHCP server for the network, and DNS if you're running AGH. Add in static clients as required, and you're off to the races. Let the router do the routing, and offload everything else to a box you can actually control.

dlockers · 11 Dec 2022 at 21:47

No need to double nat. You can run DHCP on your desktop if you want. It just dishes out a pool of IPs within a range that works.

Quartz · 11 Dec 2022 at 21:47

Rainmaker said:
Disable DHCP on the Voda router, and run dhcpd or (better yet) AdGuard Home on a Pi or similar.

Adguard Home sounds like a plan! I have a spare HP Gen8 Microserver that is probably overkill for the job but it's there. I see it's Linux-based, so which distro should I use? Bear in mind that I have near zero recent Linux / Unix experience, and never had more than a passing familiarity a decade or more ago.

Quartz · 11 Dec 2022 at 21:54

You guys sure that I will get DHCP addresses on my wifi?

dlockers · 11 Dec 2022 at 22:48

Quartz said:
You guys sure that I will get DHCP addresses on my wifi?

Yeah DHCP is pretty indiscriminate - i.e. anyone on a trusted network can broadcast DHCP (obviously controls now exist but rarely inside a home environment).

You can grab a DHCP app for your windows PC to test if you want...

Tftpd32: an opensource free firewall friendly dhcp, syslog sntp and tftp server/service for windows, tftp client

A free tftp and dhcp server for windows, freeware tftp server

pjo2.github.io

Rainmaker · 12 Dec 2022 at 02:33

Quartz said:
Adguard Home sounds like a plan! I have a spare HP Gen8 Microserver that is probably overkill for the job but it's there. I see it's Linux-based, so which distro should I use? Bear in mind that I have near zero recent Linux / Unix experience, and never had more than a passing familiarity a decade or more ago.

AdGuard Home will run on any Linux (amd64 or arm64), any *BSD, macOS, Docker or even on Windows. If you don't have any Linux experience to speak of, running your own home server with DHCP may be a stretch. Depends how interested/invested you are, but the basics really don't take long to learn nowadays. Once you've clicked next/next/next to install and learned a couple of commands (updates, copy/move/delete, edit a file) you can pick up the rest as you go. It's not a quick thing though - expect to spend months and even years learning to truly master it. Well worth it, though, and the skills are highly transferable.

~~Perhaps run under Windows if you aren't sure.~~ It seems AGH doesn't support running as a DHCP server on Windows, so it's Linux/BSD or think or something else, I'm afraid!

Quartz said:
You guys sure that I will get DHCP addresses on my wifi?

Positive. Basically, when your machines are looking for an IP they 'shout' network-wide "Is there a DHCP server anywhere, to give me an IP?". The (hopefully only) DHCP server will reply back "Yep, you can be 10.0.0.34. Your gateway is 10.0.0.1 and your DNS is 10.0.0.1. Check back in 12h.", and away you go. The client doesn't care if that DHCP server is your router, another PC, a Pi or a Docker container running in a corner somewhere. Your network just needs 'someone' to keep track of, and dish out, IPs. Your router, firewall, DNS, DHCP, WiFi and so on could literally all be individual boxes (but that'd be a waste nowadays).

Disabling DHCP on your Vodafone router simply means that your new DHCP server (and DNS server, if you go AGH) will instead say "Yep, you can be 10.0.0.34. Your gateway is 10.0.0.1 but your DHCP and DNS is me at 10.0.0.10. Check back in 12h". No drama, it's all automagic as long as the server is running and configured correctly. Here's the DHCP server in AdGuard Home (based on dnsmasq, btw):

The gateway should be your Vodafone router IP (192.168.0.1 or whatever it is). The subnet mask should be 255.255.255.0, which is a standard /24 network (254 usable IPs). The DHCP range can be whatever you like, but I suggest reserving at least the first few IPs for static configs - router, server(s), WiFi APs or whatever). I'd suggest 192.168.0.10 to 192.168.0.254 for example (or 10.0.0.10 - 254, or 172.16.0.10 - 254 etc).