Apparently the linux.conf.au domain is dead and might be for a little while. Steve Walsh writes:
Subject: Re: [Linux-aus] linux.conf.au dead?
> whois linux.conf.au
> No Data Found
The admin team noticed this about 11am this morning and notified the
registrar of the domain, who appears to have expired the domain out of
their system. We're working on getting it back into the system ASAP.
Meanwhile, http://marchsouth.org and https://conf.linux.org.au are still
up and serving conf-y goodness.