CentOS 5.5, IPv6-Only, Stateless Autoconfig and /etc/resolv.conf

[jasonvp]

Hey folks -

I've been experimenting here at home, trying to bring up an IPv6-only CentOS machine.  I've got autoconf working fine: the machine picks up its IP configuration for eth0 as well as the default route.  However, I haven't figured out a way to automatically add the DNS server to /etc/resolv.conf.

I'm running the latest RADVD daemon which does support RDNS.  But I'm pretty sure the kernel on CentOS doesn't.  My latest attempt as been with using dhcp6c and dhcp6s, just to configure the DNS server.  But I can't get it to work.  The server runs, the client kicks in and makes the request, but nothing gets dumped into /etc/resolv.conf.

The client's conf file is super-simple:

Code Select Expand


$ cat /etc/dhcp6c.conf
#
# See dhcp6c.conf(5) man page for details.
#

interface eth0 {
        information-only;
        request domain-name-servers;
};


On the server side, again, very simple:

Code Select Expand


$ cat dhcp6s.conf
option dns_servers 2001:470:e2f8:6969:20c:29ff:fe6d:5115 lateapex.net;
send information-only;


But nothing.  Is there something I'm missing or doing wrong?  Yes, I can easily add a static /etc/resolv.conf.  But I really want to see this working automatically, if possible.

Thanks.

jas

[kriteknetworks]

Instead of using dhcp, configure radvd to send rdnss data, an ipv6 nameserver IP, then install rdnssd on centos. rdnssd will pick up the nameserver IP from radvd, and write resolv.conf.

[jasonvp]

Instead of using dhcp, configure radvd to send rdnss data, an ipv6 nameserver IP, then install rdnssd on centos. rdnssd will pick up the nameserver IP from radvd, and write resolv.conf.

I already had radvd sending the data, I just didn't know what process was required to make use of it.  Thanks for the pointer, that did the trick.

Curious if anyone else has bothered trying to get dhcpv6 to work with just DNS information?

Thanks!

jas

[protologic]

I did this on FreeBSD and I struggled with this for hours in my own setup. The solution I found was to send the OtherConfigurationServer flag in my RA solicitation messages to indicate to the client that it should do a dhcpv6 request to receive information for DNS/NIS...

From what I'm seeing in the radvd.conf man page (I'm using rtadvd on FreeBSD which is different), it looks like you'll need to set the following to get it working:

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