interesting about OSX, NAT64 prefix discovery

[Mikael Abrahamsson]

On Tue, 15 Oct 2013, Mikael Abrahamsson wrote:

> On Mon, 14 Oct 2013, Michael Loftis wrote:
>
>> or dscacheutil -flushcache
>
> dhcp-28-70:Downloads mikaelabrahamsson$ dscacheutil -flushcache
> dhcp-28-70:Downloads mikaelabrahamsson$ ping6 swm.pp.se
> PING6(56=40+8+8 bytes) 2001:67c:64:47:ec62:fe83:affa:f283 --> 
> 2001:db8:624::d4f7:c88f
> 16 bytes from 2001:db8:624::d4f7:c88f, icmp_seq=0 hlim=49 time=83.997 ms
> ^C
> --- uplift.swm.pp.se ping6 statistics ---
> 1 packets transmitted, 1 packets received, 0.0% packet loss
> round-trip min/avg/max/std-dev = 83.997/83.997/83.997/0.000 ms
>
> dhcp-28-70:Downloads mikaelabrahamsson$ grep swm.pp.se /etc/hosts
> 212.247.200.143    uplift.swm.pp.se uplift swm.pp.se webmail.swm.pp.se
>
> No DNS queries were done for swm.pp.se during this above interaction, as 
> verified by tcpdump on en0.

Tore helped me figure it out.

It seems with that entry in the host field, if I ssh to swm.pp.se, it'll 
actually ssh to uplift.swm.pp.se (first entry on the line), which doesnt 
have a AAAA record, so it'll be uplift.swm.pp.se IPv4 address DNS64 mapped 
to the NAT64 prefix.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se