Reason I asked for you to check with netstat ... did it show the IPv6 for loopback only or did it also show or the IPv4.
Does your /etc/host have an entry for both IPv4 and IPv6?
What's the DCHP lease on your network? A year? Every login?
If a year, I'd set the /etc/host entry for the private IP address - IPv4 - mapped to moodle.dev.local
And you could mess with network by using arp to get an IPv4 set in a more permenant fashion.
All in all, this isn't really a moodle issue, but network/server config.