[Dnsmasq-discuss] DHCPv6 DNS server with SLAAC address

[Masin Wiedner]

Hi,

my dnsmasq server generates its IPv6 address using the prefix provided 
by my Fritz Box which itself it gets from my ISP (Telekom Germany). Up 
until now I let the Fritz Box advertise the DNSv6 server but now and 
then the Telekom hands out a different prefix breaking my DNSv6 config.

I found this old thread 
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2017q3/011737.html 
which describes a similar problem.

My takeaway from this thread is something along these lines:
 > ## IPv6 DHCPv6 DNSv6
 > enable-ra
 > ra-param=high,60,7200
 > dhcp-range=::,constructor:host0,ra-names,ra-stateless
 > dhcp-option=option6:dns-server,[fd00::]

enable-ra to make dnsmasq advertise anything at all, I guess. I don't 
really get the ra-param line. It sets the priority of dnsmasq's RA 
messages to high, I think, but I'm not sure if it's necessary when my 
Fritz Box does not provide the O flag in its RA messages. Maybe these 
messages don't get merged, though.

The dhcp-range AFAIU does not define a range at all but just tells 
dnsmasq to RA A and O flags (what are A flags?!). I want the O flag 
only, I think. ra-names seemed like a nice little addition but isn't 
necessary for my current issue.

My issue is: How can I tell dnsmasq to advertise the SLAAC generated 
IPv6 of the machine it is running on? The [fd00::] is copied from the 
thread but isn't an address assigned to an interface on the machine. Is 
there some option like "self" for its own address? Or is my approach wrong?

Bests,
Masin