[Dnsmasq-discuss] dnsmasq router advertisement/DHCPv6 configuration

[Simon Kelley]

On 29/03/2019 16:55, Marco Schuster wrote:
> Hello all,
> 
> I have a working IPv4 setup as follows:
> 1) AVM FritzBox as DSL router
> 2) Debian / dnsmasq 2.80-1 router, with eth0 being uplink to the
> FritzBox and eth1.X the client VLANs (1-16)
> 3) a couple dozen clients in the different VLANs
> 
> Now I want to expand this setup to IPv6.
> 
> The router itself has working IPv6 connectivity, with the FritzBox
> getting a /56 from the provider and distributing a /62 prefix via IA_PD
> and an IPv6 address (not in the /62 prefix but in the larger /56) via
> IA_NA to the router, with dhclient dealing with configuring eth0. An
> example prefix on eth0 would be 2001:a61:2456:b8fc::/62.
> 
> I want each VLAN IPv6 range to be set up as <prefix>:VLAN_ID:<DHCPv6
> allocation>. How do I express this with dnsmasq?
> 
> In addition: right now I have "interface=eth0, no-dhcp-interface=eth0"
> in the configuration so that machines in the FritzBox network can access
> the DNS resolver part of dnsmasq. Unfortunately, "enable-ra" enables
> router advertisements on eth0, but not on eth1.X according to the logs!
> 
> How do I prevent this and have dnsmasq only send RAs / respond to DHCPv6
> on VLANs where I explicitly state it?
> 

It should only be sending RAs on interfaces where there is a suitable
dhcp-range. Can you show more of your configuration?


Simon.