[Dnsmasq-discuss] DHCPv6 hostname resolving

[Albert ARIBAUD]

Le 02/04/2014 17:26, Quintus a écrit :
> Hi there,

Hi Quintus,

> with DHPv4, dnsmasq properly converts the hostnames send to it to A
> records we can query for. It seems however that this is not the case
> with DHCPv6 and AAAA records; while I can perfectly query for the A
> record of "atlantis.cable.internal.xxx.eu" (and even the one of
> "atlantis" without any further qualification is found), querying for its
> AAAA record just returns NXDOMAIN, i.e. it’s not found.
>
> Is this a bug, or do I have to enable that feature somehow so it works
> the same for DHCPv6 as it does for DHCPv4?

As per the manpage for dnsmasq, you should set 'ra-names' in the IPv6 
dhcp-range? e.g., instead of

> dhcp-range=set:wired6,2001:4dd0:ff00:8918:1::2,2001:4dd0:ff00:8918:1:ffff:ffff:fffe,80,6h
> dhcp-range=set:wifi6,2001:4dd0:ff00:8918:2::2,2001:4dd0:ff00:8918:2:ffff:ffff:fffe,80,6h

Use

dhcp-range=set:wired6,2001:4dd0:ff00:8918:1::2,2001:4dd0:ff00:8918:1:ffff:ffff:fffe,80,6h,ra-names
dhcp-range=set:wifi6,2001:4dd0:ff00:8918:2::2,2001:4dd0:ff00:8918:2:ffff:ffff:fffe,80,6h,ra-names

 From the manpage:

"ra-names  enables  a  mode  which  gives DNS names to dual-stack
hosts which do SLAAC for IPv6.  Dnsmasq  uses  the  host's  IPv4
lease  to  derive  the name, network segment and MAC address and
assumes that the host will also have an IPv6 address  calculated
using  the  SLAAC  algorithm,  on  the same network segment. The
address is pinged, and if a reply is received, an AAAA record is
added  to  the DNS for this IPv6 address. Note that this is only
happens for directly-connected networks, (not one doing DHCP via
a  relay) and it will not work if a host is using privacy exten-
sions.  ra-names can be combined  with ra-stateless and slaac."

Amicalement,
-- 
Albert.