This is a follow up to my previous post on preparing my Ubuntu 19 system for travel. I've had to re-enable IPv6 on my Ubuntu laptop for a couple reasons which I'll discuss below. This wouldn't normally be post-worthy, except to help anyone else seeing the same errors due to disabling IPv6.
GPSd wants it
I've needed to run GPSd recently to work with a USB GPS device. Apparently GPSd really wants to bind to an IPv6 address. There's probably a way to make it not want this, but since I have other reasons to use IPv6 anyway, I'll just go ahead and enable it.
Just in case someone else comes across this error, here are the log messages that tipped me off:
gpsd.socket: Failed to listen on sockets: Cannot assign requested addressand
gpsd:ERROR: can't bind to IPv6 port gpsd, Cannot assign requested address
6LoWPAN
The 6 in 6LoWPAN means IPv6. There are some 6LoWPAN challenges at the Wireless CTF, and I'll need to be able to speak IPv6 to complete them (at least the challenges that require TX).
FYI: the device I'm using for 6LoWPAN is the openlabs 802.15.4 radio for the Raspberry Pi.
Do The Thing
Anyway, if you've disabled IPv6 via sysctl.conf, make sure the following lines are commented:
#net.ipv6.conf.all.disable_ipv6=1 #net.ipv6.conf.default.disable_ipv6=1 #net.ipv6.conf.lo.disable_ipv6=1
