Persistent sysctl Settings

Not actually a question, but the thread I wanted to reply to is locked.

The linked discussion is seeking to persist kernel parameters such as

net.inet6.send.opmode=0

I also find that /etc/sysctl.conf is ignored. However, I found that using a launchctl system daemon does work as recommended in this forum answer. Here is the job definition:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>sysctl</string>
	<key>ProgramArguments</key>
	<array>
		<string>/usr/sbin/sysctl</string>
		<string>net.inet6.send.opmode=0</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
</dict>
</plist>

saved in /Library/LaunchDaemons/sysctl.plist. Somewhat surprisingly, this worked perfectly for me, resulting in a stable IPv6 address.