IPv6 aliases on FreeBSD 10

[pepe]

I know it's usually done with /64, but my ISP just said: your block is
2001:14b8:1801::/48 and
defaultrouter should be ::1. So I can't really change that.

My rc.conf was like that when I copied it from fbsd 8 server, but new
server is fbsd 10 so ipv6 section is like this:

ifconfig_em0_alias59="inet 62.165.159.154 netmask 255.255.255.255"
ipv6_activate_all_interfaces="YES"
ipv6_defaultrouter="2001:14b8:1801::1"
ifconfig_em0_ipv6="inet6 2001:14b8:1801:c001::1 prefixlen 48"
ifconfig_em0_alias60="inet6 2001:14b8:1801:c001::2 prefixlen 48"
ifconfig_em0_alias61="inet6 2001:14b8:1801:c001::3 prefixlen 48"
ifconfig_em0_alias62="inet6 2001:14b8:1801:c001::4 prefixlen 48"
ifconfig_em0_alias63="inet6 2001:14b8:1801:c001::5 prefixlen 48"
ifconfig_em0_alias64="inet6 2001:14b8:1801:c001::6 prefixlen 48"
ifconfig_em0_alias65="inet6 2001:14b8:1801:c001::7 prefixlen 48"
ifconfig_em0_alias66="inet6 2001:14b8:1801:c001::8 prefixlen 48"
ifconfig_em0_alias67="inet6 2001:14b8:1801:c001::9 prefixlen 48"
ifconfig_em0_alias68="inet6 2001:14b8:1801:c001::10 prefixlen 48"
ifconfig_em0_alias69="inet6 2001:14b8:1801:c001::42 prefixlen 48"


On Thu, Oct 23, 2014 at 4:49 PM, Jon Radel <jon at radel.com> wrote:

> On 10/23/14, 1:19 AM, pepe wrote:
>
>> prefix 128 didn't work either. only first real address is working. none of
>> the aliases work with 48, 64 or 128...
>> our network is 2001:14b8:1801::/48 so that prefixlen 48 is right for ::1
>> address isn't it? and well, it works so
>> I think it is right...
>>
>>
> It would be rather unusual to have a /48 there.  There are many things in
> IPv6 that assume you're using a /64 network on each LAN segment / collision
> domain / however-you-want-to-think-of-it.  So while, in some senses,
> using a /48 there isn't *wrong*, after all, one might need to have 1.208 x
> 10^24 addresses on a single LAN segment [but so much else would break], in
> your case it's probably wrong.
>
> Things will probably go more smoothly in general if you use IPv6-think:
>  You were assigned 2^16 (65,536) networks (each a /64).   You were *not*
> assigned 2^80 addresses.  (Obviously you were actually assigned 2^80
> addresses, but that's really not a useful way to think of IPv6 addresses
> when planning your network.)
>
> Assign a /64 to the network this machine is connected to.  Obviously other
> equipment has to play along and have a matching prefix length.
>
> You might also want to show us what is in your rc.conf, not just what
> ifconfig reports.  Here's an example from an 8.3 server:
>
> ipv6_ifconfig_fxp0="2001:470:880a:5237::10:1 prefixlen 64"
> ipv6_ifconfig_fxp0_alias0="2001:470:880a:5237::12:1 prefixlen 128"
> ipv6_ifconfig_fxp0_alias1="2001:4830:1707:5237::10:1 prefixlen 64"
> ipv6_ifconfig_fxp0_alias2="2001:4830:1707:5237::12:1 prefixlen 128"
> ipv6_defaultrouter="2001:470:880a:5237::1"
>
> That works fine.
>
> --Jon Radel
> jon at radel.com
>
>
>


-- 
pepe