[pkg-dhcp-devel] Bug#849378: IPv6: dhclient: ignores supersede, appaned and prepend

Daniel Pocock daniel at pocock.pro
Mon Dec 26 13:00:39 UTC 2016

Package: isc-dhcp-client
Version: 4.3.1-6+deb8u2

I'm running dual stack IPv4 and IPv6

The Debian (client) machine has NM disabled


iface eth0 inet dhcp
iface eth0 inet6 dhcp
	accept_ra 1

The DHCPv6 server only sends one search domain but I want to use two
search domains.

I tried adding both of them in /etc/dhcp/dhclient.conf using supersede,
append or prepend, all of those options appear to be ignored, e.g.

append domain-search "subdomain1.example.org", "subdomain2.example.org";
append dhcp6.domain-search "subdomain1.example.org",

has no effect.

If I run the dhclient manually, I notice these directives work correctly
for IPv4

I used strace to verify that the IPv6 instance of dhclient is definitely
reading /etc/dhcp/dhclient.conf

The DHCPv6 server only sends subdomain1.example.org but that is the
problem I'm trying to workaround by using supersede, appaned or prepend

I tried running dhclient with "-v -d" and also looking at syslog and
journalctl and couldn't find any hints about it ignoring or rejecting
these search parameters.

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