Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Reverse-path forwarding
open-in-new
<p>Reverse-path forwarding (RPF) is a technique used in modern <a href="/facts/Router_(computing)/Nh5cIyVf">routers</a> for the purposes of ensuring loop-free forwarding of <a href="/facts/Multicast/D9IspSfl">multicast</a> packets in <a href="/facts/Multicast_routing/01LGJsbF">multicast routing</a> and to help prevent <a href="/facts/IP_address_spoofing/W7Ba2do5">IP address spoofing</a> in <a href="/facts/Unicast/PHStTfFe">unicast</a> routing. </p><p>In standard unicast IP routing, the router forwards the packet away from the source to make progress along the distribution tree and prevent routing loops. In contrast, the router's multicast forwarding state runs more logically by organizing tables based on the reverse path, from the receiver back to the root of the distribution tree at the source of the multicast. This approach is known as reverse-path forwarding. </p>