When IPv6 temporary addresses are regenerated?

[Frank Behrens]

As nobody made a reply I will reply myself. ;-)

Frank Behrens <frank at pinky.sax.de> wrote on 25 Jan 2007 14:09:
> I have an IPv6 setup with temporary addresses (RFC3041). To switch this on I used "sysctl 
> net.inet6.ip6.use_tempaddr=1". The temporary address is generated and meanwhile expired. 
> 
> Does anybody know, when this address is expected to be regenerated?

Short answer after digging in the sources:
A new temporary address is regenerated, when there is another address configured with flag 
"autoconf" (and temporary address is deprecated).

The specification says, the temporary addresses should be generated for interfaces setup 
with stateless address autoconfiguration. What for a setup do I have? My FreeBSD router is 
connected via PPP, so I inserted the assigned _prefix_ in rc.conf. Now I have a half 
autoconfiguration, the prefix is assigned statically combined with IEEE identifiers.
You see that in my current config:
>         inet6 2xxx:xxxx:xxxx:0:211:2fff:xxxx:xxxx prefixlen 64
>         inet6 2xxx:xxxx:xxxx:0:54b:5960:xxxx:xxxx prefixlen 64 deprecated autoconf temporary pltime 0 vltime 509995

But we can change the autoconf interface attribute with the undocumented ifconfig(8) flag 
with same name. In that case all works as expected.

To achieve this as simple as possible I changed my rc.conf from
ipv6_prefix_vlan0="2xxx:xxx:xxxx:x"
to
ipv6_ifconfig_vlan0="2xxx:xxx:xxxx:x:: prefixlen 64 eui64 autoconf"

The site effect is, that there is now no automatic assigment of a 64 bit anycast address for 
this interface, but that does not matter in my setup.

So my problem is solved, maybe someone can document the behaviour.

Gruß,
   Frank
-- 
Frank Behrens, Osterwieck, Germany
PGP-key 0x5B7C47ED on public servers available.