[ipv6hackers] dynamic global hostname

Iljitsch van Beijnum iljitsch at muada.com
Fri Oct 7 22:26:00 CEST 2011

This is pretty cool: on my Mac running 10.7 if I set a dynamic global hostname in the sharing settings, I get:

dulcinea:~ iljitsch$ host dulcinea.bonjour.muada.nl
dulcinea.bonjour.muada.nl has address
dulcinea.bonjour.muada.nl has IPv6 address 2001:720:410:100f:7928:189c:e351:8001

That's at work. At home I'm behind a pretty dumb NAT and then:

dulcinea:~ iljitsch$ host dulcinea.bonjour.muada.nl
dulcinea.bonjour.muada.nl has IPv6 address 2001:470:1f0b:1289:e8b3:2400:d959:f2a9

This also worked under MacOS 10.4 but as of 10.5 IPv6 addresses were no longer registered using dynamic DNS updates because with the IETF mandate for a stateful firewall the thinking was that for IPv6 incoming sessions were even less likely to work than for IPv4, where at least there's NAT-PMP and uPNP IGD.

Interestingly, most of the time my temporary address is put in the DNS but one time it was the MAC-derived address.

If you want to experiment, bonjour.muada.nl accepts dynamic updates without authentication. But remember that if you enable advertising services this is exactly what happens and anyone can see what services you run on which address/port.

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