FreeBSD ipv6 rc.conf settings issue

Matthew Seaman m.seaman at
Sat Jan 9 10:56:46 UTC 2010

Gary Kline wrote:

> This caught my interest this morning so I set up a commented-out trial in
> /etc/rc.d for my ipv6 entry; the one I had in my database /etc/namedb/* files
> blew my connection sky-high recently.
> Does this seem plausible:
> #
> ## ipv6 config
> #
> # ipv6_enable="YES"
> # ipv6_defaultrouter="2002:d1b4:d5d2::"
> # ipv6_default_interface="em0"
> # ipv6_gateway_enable="YES"
> given that my Adress record is ?
> tia, gents,

So you're using 6to4 tunnelling as described in stf(4)?  That's a quite
different setup to what has been discussed previously in this thread. 
I think 6to4 is, if not deprecated, certainly not the normal way of getting
IPv6 connectivity nowadays.  Generally you'ld get an address space allocation
from your ISP, or failing that, a tunnel broker like Hurricane Electric[*].

Anyhow, as stf(4) says, you need to encode your IPv4 address as hex in the
6to4 address -- that looks correct:

% perl -e 'map { printf "%x\n", $_ } split( /\./, shift );'

However 2002:d1b4:d5d2:: is *your* network address, and having it as the default router sounds wrong to me.  You need to assign addresses from that
range to your hosts -- which you can do automatically by enabling rtadvd(8)
on your gateway machine and rtsold(8) on your clients.  Also, to use 6to4
you need to create a 'stf0' interface and make that the ipv6_default_interface.

This is all independent of setting up IPv6 related items in your DNS.  Get
the IPv6 connectivity working first -- use ping6 and traceroute6 with IPv6
numbers to confirm connectivity, and then worry about DNS settings.



[*] Which is pretty crazy given that the prediction is IPv4 space is
going to run out around 2012[+].  All of the major ISPs and NSPs really
should be providing IPv6 natively by now.

[+] Potential for another IT-feeding-frenzy-panic scenario like the run
up to Y2K.  Make sure IPv6 is on your CV...

Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                  Flat 3
PGP:     Ramsgate
                                                  Kent, CT11 9PW

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 259 bytes
Desc: OpenPGP digital signature
Url :

More information about the freebsd-questions mailing list