dhcpv6 server configuration

Shane Kerr Shane_Kerr at isc.org
Mon Nov 19 16:32:02 UTC 2007

Hash: SHA1


Yeung, Pauline wrote:
> I'm running dhcp 4.0.0b2 in two linux PC's, each with three NIC's.  The
> following shows the information on the server.
>> uname -rm
> i686
>> /usr/local/sbin/dhcpd --version
> isc-dhcpd-4.0.0b2
>> ifconfig
> eth0      Link encap:Ethernet  HWaddr 00:90:27:1C:BC:70
>           inet addr:  Bcast:  Mask:
>           inet6 addr: fe80::290:27ff:fe1c:bc70/64 Scope:Link
> :
> eth1      Link encap:Ethernet  HWaddr 00:11:25:4F:9E:7B
>           inet addr:  Bcast:  Mask:
>           inet6 addr: fe80::211:25ff:fe4f:9e7b/64 Scope:Link
> :
> eth2      Link encap:Ethernet  HWaddr 00:19:5B:71:38:50
>           inet addr:  Bcast: 
> Mask:
>           inet6 addr: fe80::219:5bff:fe71:3850/64 Scope:Link
> :
> I'm using the following configuration file
> subnet6 fec0:aaaa:bbbb:cccc::/64 {
>      range6 fec0:aaaa:bbbb:cccc::10 fec0:aaaa:bbbb:cccc::fd;
>      preferred-lifetime 360;
> }

All of these IPv6 addresses are "link local". You can read about them here:


In order to use the DHCPv6 server, you need to have addresses with global scope.
Or "real" IPv6 addresses.

For testing, I sometimes use 6to4 addresses. The interesting thing about 6to4
for testing purposes is that if you have an IPv4 address, you can convert it to
an IPv6 network that you know is available, at least for a short while (you can
see on the bottom of the page):


So for my computer here I have, which is 2002:C706:01EF::/48. For
testing I can give my interface an address from this network:

# ifconfig eth1 add 2002:c706:01ef:0001::1/64

Then I can test the DHCP server by setting the appropriate information in the
configuration file:

subnet6 2002:c706:01ef:0001::1/64 {
     range6 2002:c706:01ef:0001:8000::/65;

(Your second e-mail, about the core dump, is possibly related, but we should
fail gracefully - I'm looking into that now.)

- --
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org


More information about the dhcp-users mailing list