dhclient on Debian Jessie not sending the same identifier for DHCPv4 and DHCPv6 (RFC 4361)

Nicolas C. dhcp at nryc.fr
Tue Sep 8 22:51:07 UTC 2015

Le 08/09/2015 17:15, Shawn Routhier a écrit :
> Try the -df option to the client.
> This provides a method to share a DUID between the two clients.

Thanks, it works when I manually start the DHCPv6 client...

dhclient -6 -v -I -D LLT eth0

...and then the DHCPv4 client, with the "-df" option pointing to the 
lease file just updated by the DHCPv6 client...

dhclient -4 -v -I -D LLT -df /var/lib/dhcp/dhclient6.leases eth0

...and in the forward zone, I have both records!

dual-test.rfc4361.test. 300     IN      A
dual-test.rfc4361.test. 187     IN      DHCID 
dual-test.rfc4361.test. 187     IN      AAAA    2001:660:3305:122::ec2

Now the big question is : how can this be done automatically at bootup? 
I tried to delay the DHCPv4 client with this :

auto eth0
iface eth0 inet6 dhcp

iface eth0 inet dhcp
   pre-up sleep 5

And a shell script /sbin/dhclient calling the real binary with correct 
options but it doesn't work, is it worth trying with a Debian Jessie 
without SystemD?

I suppose it's a job for the maintainer of the "ifupdown" package in Debian?



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