[colug-432] IPv6 adventures

Rob Funk rfunk at funknet.net
Fri Sep 4 15:51:36 EDT 2015

Jim Wildman wrote:
> I was incorrect on the temp addresses for Linux.
> Apparently you need all of
> net.ipv6.conf.all.use_tempaddr=2
> net.ipv6.conf.default.use_tempaddr=2
> net.ipv6.conf.eth0.use_tempaddr=2
> in /etc/sysctl.conf or /etc/sysctl.d/something.conf and then reboot.

It looks like Ubuntu made 2 the default in

# IPv6 Privacy Extensions (RFC 4941)
# ---
# IPv6 typically uses a device's MAC address when choosing an IPv6 address
# to use in autoconfiguration. Privacy extensions allow using a randomly
# generated IPv6 address, which increases privacy.
# Acceptable values:
#    0 - don't use privacy extensions.
#    1 - generate privacy addresses
#    2 - prefer privacy addresses and use them over the normal addresses. 
net.ipv6.conf.all.use_tempaddr = 2
net.ipv6.conf.default.use_tempaddr = 2

This is probably a factor is the behavior I see.

I suspect that the resolution to my issue is just to set up static
addresses rather than expecting dynamic addresses (presumably from a
radvd server I don't control?) to act the way I'm used to.

Thanks for all the information!

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