Dual ISP network issues now that Vodafone IPv6 is rolling out

[__graeme]

Apologies, this isn't a quick question .

Background:

I have 2 ISPs Vodafone and Virgin.

I run my own DHCP and DNS.

Virgin Router is 192.168.0.1 - Wifi and DHCP are turned off

Vodafone Router is 192.168.0.2 - Wifi and DHCP are turned off
Wifi is provided by separate Wireless Access Point
Via my DHCP server, devices on my network are assigned a gateway of either 192.168.0.1 or 192.168.0.2 and DNS of 192.168.0.11  

My DNS server on 192.168.0.11 uses googles DNS servers upstream. 8.8.8.8 and 8.8.4.4   
I have 60+ devices on my network. 

IPCONFIG snippet (redacted)

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : xxxxxxxxxxxxxx.co.uk
Description . . . . . . . . . . . : Atheros AR8151 PCI-E Gigabit Ethernet Controller (NDIS 6.20)
Physical Address. . . . . . . . . : 90-2B-34-xx-xx-xx
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : fd52:a81c:xxxxxxxxxxxxxx
Temporary IPv6 Address. . . . . . : fd52:a81c:xxxxxxxxxxxxxx
Link-local IPv6 Address . . . . . : fe80::d2:ef9c:7984:3155%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.0.25(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 03 March 2020 00:41:21
Lease Expires . . . . . . . . . . : 11 March 2020 12:41:49
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.11
DHCPv6 IAID . . . . . . . . . . . : 2443nnnnn
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-CA-xx-xx-xx-xx-xx-xx-xx
DNS Servers . . . . . . . . . . . : fd52:a81c:xxxxxxxxxxxxxx
192.168.0.11
NetBIOS over Tcpip. . . . . . . . : Enabled
Connection-specific DNS Suffix Search List :
broadband

The issue:

Until very recently my network setup worked fine but today I'm getting website timeouts and various other issues. A quick look at my IPCONFIG on my desktop machine (and IP ADDRESS on my Linux machine) and I'm seeing IPv6 DNS server ahead of my DNS server. It seems that my Vodafone router has assigned IPv6 addresses to every device on my network that can handle one. Any device with IPv6 address has now got a IPv6 DNS ahead of mine.  This has taken away my control of my network. If a device is served an IPv6 addess by the IPv6 DNS server then all traffic for that remote IPv6 site is routed via my Vodafone Router. Even if my IPv4 DHCP service has directed that device to use my Virgin Router as a gateway. Messy. 

So, my question:    
I accept that I'm going to have to migrate my DHCP/DNS server for IPv6 at some point but I don't know enough about IPv6 to take that on right now.  What I need right now is to disable IPv6 or at least IPv6 DHCP/DNS on my Vodafone router. Trouble is, I don't seem to be able to find that option, even in expert mode.
Any suggestions anyone?

Thanks in advance,

Graeme

[unmesh90vaidya]

Actually my DNS provider says that they only work with IPv4 so even dual stack will not work. I must disable IPv6 to access DNS. 

[CrimsonLiar]

If you are using a specialised 3rd Party DNS (such as the SDNS Proxy I have set up on a Pi-Hole), these may only provide IPv4-based DNS.  If there is no means to turn off IPv6 on the router, then the only answer I can think of is to use a VPN or change DNS service!

[unmesh90vaidya]

Understood, thanks for your help.

[Jayach]

---

@Cynric wrote:

.@mrwhitey I am assuming that you are not using IP6 on your LAN as you are happy to turn it off in the router. Given that, have you disabled IP6 on the Windows computers (Control Panel -> Network and Sharing Centre ->  Change Adapter Settings -> right-click the adapter -> Properties -> untick Internet Protocol Version 6).

---

@mrwhitey posted before Russia invaded Ukraine. I suspect he has probably resolved his problem by now. 🤣

[Cynric]

.@Jayach This is true 😁 I blame having one eye on the television and the other on the bottle of Rioja.

[__graeme]

I guess the "IPv6 learning" has begun. Looks like the DHCP type stuff is handled by the VF Router sending "Router Advertisements", totally bypassing my DHCP server.  

[Alex882]

Try turning off IPv6 on the router: Expert mode / Local network / Network settings / IPv6

[__graeme]

@alex882

Is it this setting ?  I'm not seeing "Local network" or "Network settings" in the Expert settings.  
I've turned it off but I think my network devices won't be happy now until they next renew their leases.

[unmesh90vaidya]

I am from germany but i cannot find this option to disable IPv6 now, how can i do it? Do you have any guidance?

[Jayach]

This is a U.K. forum, so we have no idea what router you use.

Vodafone haven't got IPv6 working here yet.

Try here: Home - Vodafone Community