A host SHOULD NOT send an ICMP Redirect message; Redirects are to be sent only by gateways.
A host receiving a Redirect message MUST update its routing information accordingly. Every host MUST be prepared to accept both Host and Network Redirects and to process them as described in Section 3.3.1.2 below.
A Redirect message SHOULD be silently discarded if the new gateway address it specifies is not on the same connected (sub-) net through which the Redirect arrived [INTRO:2, Appendix A], or if the source of the Redirect is not the current first-hop gateway for the specified destination (see Section 3.3.1).