18.04 - How to disable temporary/privacy IPv6 addresses?

Solution 1:

I had the same problem. I first tried to disable ipv6 autoconf and accept_ra in sysctl.conf

# sysctl -p
net.ipv6.conf.all.autoconf = 0
net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.lan.autoconf = 0
net.ipv6.conf.lan.accept_ra = 0
net.ipv6.conf.wan.autoconf = 0
net.ipv6.conf.wan.accept_ra = 0

But that did not change anything. Since netplan has some timing problems I disabled accept_ra in netplan yaml file.

/etc/netplan/50-cloud-init.yaml

addresses:
- xxx.xxx.xxx.xxx/24
- xxxx:xxxx:xxxx::xx/64
dhcp4: false
dhcp6: false
accept-ra: false