I'm a new Linux user as well, so this may be obvious to everyone else but I got caught out until I realised that Ubuntu overwrites changes made to sysctl.conf when you reboot unless you use the correct command to edit the file.
The command is:
sudo gedit /etc/sysctl.conf
If you just edit the file without 'sudo' then the changes will be overwritten on reboot.
I'm a new Linux user as well, so this may be obvious to everyone else but I got caught out until I realised that Ubuntu overwrites changes made to sysctl.conf when you reboot unless you use the correct command to edit the file.
The command is:
sudo gedit /etc/sysctl.conf
If you just edit the file without 'sudo' then the changes will be overwritten on reboot.
Hope this helps!