This read-create value enables or disables sending of ICMPv6 redirect messages that tell a host to resend a packet through the same interface it arrived on, when a better next hop exists. An admin disables this on interfaces where redirect messages could leak topology information or aren't useful, or enables it to help end hosts find optimal routes automatically. For example, disabling it on a perimeter interface prevents the router from revealing internal routing shortcuts to devices outside the trusted network.