Fix to prevent unknown key errors during system startup

From Gentoo Linux Wiki

[edit] Fix to prevent unknown key errors during system startup

Errors may occur during the "Configuring kernel parameters" system initialization stage.

Configuring kernel parameters ... error net.ip4.conf.default.rp_filter is an unknown key error net.ip4.conf.all.rp_filter is an unknown key

[edit] These errors are non critical and can be ignored

The errors are due to the startup scripts trying to modify the configuration of the kernel using the optional sysctl interface, on a kernel that does not support dynamic configuration changes via sysctrl.

[edit] Preventing the errors

It is necessary to edit the /etc/sysctl.conf file, and comment out all entries from the file. Alternatively, the bootmisc script could be modified, removing the sysctrl code.