Packet forwarding

Packet forwarding is the relaying of packets from one network segment to another by nodes in a computer network.

Models

A unicast forwarding pattern, typical of many networking technologies including the overwhelming majority of Internet traffic

A multicast forwarding pattern, typical of PIM

A broadcast forwarding pattern, typical of bridged Ethernet

e simplest forwarding model‍—‌unicasting‍—‌involves a packet being relayed from link to link along a chain leading from the packet's source to its destination. However, other forwarstrategies are commonly used. Broadcasting requires a packet to be duplicated and copies sent on multiple links with the goal of delivering a copy to every device on the network. In practice, broadcast packets are not forwarded everywhere on a network, but only to devices within a broadcast domain, making broadcast a relative term. Less common than broadcasting, but perhaps of greater utility and theoretical significance, is multicasting, where a packet is selectively duplicated and copies delivered to each of a set of recipients.

See also

• Equal-cost multi-path routing
• Forwarding information base
• Node-to-node data transfer
• Per-hop behaviour
• Port forwarding