Configure Sending and Accepting Shared Media Redirects for All IPv4 Interfaces

Description

To set the runtime status of the net.ipv4.conf.all.shared_media kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.shared_media=

To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:

net.ipv4.conf.all.shared_media = 

Rationale

This setting should be aligned with net.ipv4.conf.all.secure_redirects because it overrides it. If shared_media is enabled for an interface secure_redirects will be enabled too.