ipv6, stateful config and non-default prefixlen

JINMEI Tatuya / 神明達哉 jinmei at isc.org
Fri Mar 18 18:29:22 UTC 2011

At Fri, 18 Mar 2011 21:35:16 +0500,
"Eugene M. Zheganin" <eugene at zhegan.in> wrote:

> > You don't say what prefix length rtadvd is sending or that you're seeing
> > in the wireshark log.
> >
> > Do you have prefixlen#120 in your rtadvd.conf?

Whether using /120 is a good idea might have to be debated, but anyway..

> %ps ax | grep dhc
> 25672  ??  Is     0:00,01 /usr/local/sbin/dhclient -6 nfe0

I guess this is ISC DHCP.  It always assumes /64 and (effectively)
installs the given address this way:

# ifconfig nfe0 inet6 fd00::7d2/64 alias

A possible workaround is to rewrite dhclient-script to hardcode
"/120".  Another solution is to use a different DHCPv6 client
implementation.  (Although it's not actively maintained/enhanced
recently) I believe WIDE DHCPv6 should work for your purpose:

JINMEI, Tatuya
Internet Systems Consortium, Inc.

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