[CentOS] DHCPv6 - requesting "other" information

Thu Oct 9 04:15:51 UTC 2014
Mike Mohr <akihana at gmail.com>

Hello;

I've run into a rather interesting problem on CentOS 7.  According to
sysconfig.txt (part of the initscripts documentation), I can set the
following variables in ifcfg-ethX:

DHCPV6C="yes"
DHCPV6C_OPTIONS="-S"

I've done so, but nothing is populated to /etc/resolv.conf and so DNS does
not work.  Interestingly, if I remove the latter option, an IPv6 address is
added to the relevant interface.  Packet dumps indicate that the required
DNS information is being sent over the wire, so this appears to be a bug in
the IPv6 DHCP software.  Running the following command by hand yields
similar results:

$ dhclient -6 -S -v -v eth1

i.e. there are informational messages printed indicating that a DHCPv6
response was received successfully.  Packet dumps again confirm that DNS
information is being sent over the wire, but is not being used by the DHCP
client application.

Is this a known issue, and is there a way to fix the problem?

All the best,
Michael