rc settings for ipv6 in 9.3?

[Kevin Oberman]

On Tue, Jun 30, 2015 at 5:29 PM, <kpneal at pobox.com> wrote:

> I just got a /56 block of ipv6 addresses today and I'm trying to figure
> out how to use it.
>
> Before I go rebooting my server I wanted to ask if the information in the
> handbook "https://www.freebsd.org/doc/handbook/network-ipv6.html" is
> correct
> for 9.3-p14.
>
> I have a static address for my server and I've been given the static
> address of the router. So I should just be able to set (in my rc.conf)
> ifconfig_bce0_ipv6 and ipv6_defaultrouter, correct?
>
> Or do I really need these two lines from the handbook?:
> ifconfig_bce0_ipv6="inet6 accept_rtadv"
> rtsold_enable="YES"
>
> Also, can someone translate this statement from my provider for me:
> "Note: [provider] is routing 2607:f758:2280::/56 to 2607:f758:2280::4/64"
>
> BTW, is the term "netmask" ever used in IPv6? I thought "prefixlen" was
> the term and "netmask" was for v4 only?
>
> Thanks for any help!
> --
> Kevin P. Neal                                http://www.pobox.com/~kpn/
>

No, If your system has a static address (and a server should have one), you
don't need SLAAC or Router Solicitation. You just need to set the address:
 ifconfig_bce0_ipv6="inet6 2607:f758:2280::n/64" and
ipv6_defaultrouter="Router address".

Netmasks are obsolete everywhere and really should not be used. CIDR
addressing has been the standard for a quarter century. Netmasks really
should not be used for either IPv4 or IPv6.

I am unable to translate the statement from the provider with certainty. I
am guessing that the /64 2607:f758:2280::/64  is used by their router with
2607:f758:2280::4 as the address on their router(s).  The remainder of the
/56 is yours but I could not swear to that.

You will probably want more than one /64 for different purposes. Other than
externally accessible servers, you should put systems in a different /64
and spread them at random around that space if they are statically
addressed. (I don't recommend for or against statically addressing, though.)
--
Kevin Oberman, Network Engineer, Retired
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683