link local address being assigned as a default gateway

[OzziGoblin]

Hi everyone
 
I'm hoping someone else has encountered this and is able to tell me a solution.
 
I have recently upgraded to 26.1.3 and I'm not sure if this issue occurred before or not, but I am getting a Link local address assigned as a IPv6 gw entry on my internal network interfaces and the firewalls eui-64 address for DNS.
 
My config is as follows:

• I use Adguardhome for primary DNS on port 53
• Unbound for reverse lookups on port 53530
• fw rules & NAT force all DNS traffic to us internal DNS servers for name resolution as much as possible.
• I use ISC DHCP & v6 with router advertisements.
• No DNS entry is configured in router advertisements.
• WAN interface is set to DHCP
• internal interfaces are set to track the WAN interface with a prefix added for each unique interface.

 
The  DNS entry is a problem because Windows, if IPv6 is available, defaults to using it so reverse and forward lookups are failing and it eventually reverts to IPv4.  Nslookups fail as do pings to dns names.
 
AI suggests removing IPv6 completely as the solution, thing is, this used to work.
 
Is anyone aware of a fix for this or where I could be going wrong in my config?
 
thanks

[OzziGoblin]

I think I resolved this.  It appears to be because "Allow manual adjustment of DHCPv6 and Router Advertisements" wasn't selected on the interface and for some reason "Enable DHCPv6 server on LAN interface" was enabled on the DHCPv6 ISC setting for each interface.  

Name resolution is now working, but ping for ipv6 addresses is still erratic.

maybe this will help someone else.