IPv6 DNS coming from Meraki MR16 access Point with pfSense router

I have a network consisting out of a pfSense 2.3 router, and 2 Cisco Meraki MR16 access points. The pfSense Box is connected to Comcast on the WAN interface, and provides one LAN segment. The MR16's are both connected to the LAN side, and are configured in bridging mode.
pfSense is configured in Track mode for IPv6, and is both the DNS v4 server at 192.168.2.1 and DNSv6 FE80::1:1.

Both MR16's run LEDE Reboot 17.01.3 (same problem happend with LEDE Reboot 17.01.2.

I have a very weird issue happening. My DNS server settings on my windows 7 pro workstations show: (ipconfig /all) - pubilc IPv6 addresses removed! -

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : home.lan
   Description . . . . . . . . . . . : Intel(R) Ethernet Connection (2) I218-V
   Physical Address. . . . . . . . . : 78-24-AF-89-E0-0D
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : xxxx:yyy:zzzz:qqqq:6c4a:56cd:d88d:5828(Preferred)
   Temporary IPv6 Address. . . . . . : xxxx:yyy:zzzz:qqqq:f82e:b32:143:62c0(Preferred)
   Link-local IPv6 Address . . . . . : fe80::6c4a:56cd:d44d:5828%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.2.190(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Tuesday, October 10, 2017 21:40:47
   Lease Expires . . . . . . . . . . : Tuesday, October 10, 2017 23:40:47
   Default Gateway . . . . . . . . . : fe80::1:1%11
                                       192.168.2.1
   DHCP Server . . . . . . . . . . . : 192.168.2.1
   DHCPv6 IAID . . . . . . . . . . . : 242754735
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-4C-8A-72-78-24-AF-89-E0-0D
   DNS Servers . . . . . . . . . . . : **fe80::218:aff:fe38:cd6a%11**
                                       192.168.2.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

The trouble is with the DNS address for the IPv6 network. It is a link/local address of one of my Meraki's. This is wrong. I took a wireshark trace and see it going to the MR16, but NOT intended. I see an ICMP6 reply from the MR16 that it is a DNS server. (not)

I played around with the IPv6 settings, and also the DNS/DHCP settings, removed dnsmasq and different things. I set the forwarding IPv6 address for DNS to the pfSense box to no avail.

I am considering compiling the MR16 code with IPv6 disabled, but not sure whether that will break things for my WiFi clients. Both the hardwired and WiFi clients show the problem...

What can be done to fix this problem?

Laaf

You need to disable odhcpd as well, which is the component to deal with the IPv6 side if things.

That doesn't do it. I even went as far to build my own LEDE build, where I took odhcpd OUT of it, and the Windows 7 machines still get that router's address as a DNS server.

Ok. I did a test - which went bad. I loaded OpenWrt Chaos Calmer over this code, and it actually bricked the A/P. I could try to correct it, however given the fact that an MR16 is about $20-$30 on ebay, it might not be worth it.

If someone wants to do the experiment and repair a bricked MR16 - send me a private mail - you can have it for postage in the US.

I had to add these settings to sysctl.conf

net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6 = 1

to make things work.