If you are disabling IPv6 then you likely know why you are doing it and the reasons may be varied. Disabling IPv6 only requires a brief search to find the sysctl change required but the Ubuntu bug issue is worth a mention.
Modify the following file:
# vim /etc/sysctl.d/99-sysctl.conf
Add the following lines:
net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1
Reload values and confirm IPv6 addresses have been removed:
# sysctl -p
There appears to a bug in Ubuntu affecting the sysctl settings loading after reboot.
The fix however is to create a new file /etc/rc.local and add these contents:
#!/bin/bash # /etc/rc.local # Load kernel variables from /etc/sysctl.d /etc/init.d/procps restart exit 0
You’ll need to ensure the file is executable as well:
chmod 755 /etc/rc.local
Thanks to Bill for his post which likely saved me time searching the interweb for answers…