<Li> Quality of service (QoS) </Li> <P> The switching algorithm is relatively simple and is the same for most of the routed protocols: a host would like to send a packet to a host on another network . Having acquired a router's address by some means, the source host sends the packet directly to that router's physical (MAC) address . The protocol (network layer) address is that of the destination host . </P> <P> The router examines the packet's destination protocol address and determines whether it knows how to forward the packet or not . If the router does not know how to forward the packet, it typically drops the packet . If it knows how to forward packet, it changes the destination physical address to that of the next hop router and transmits the packet . </P> <P> The next hop may be the destination or the next router, which executes the same switching process . As the packet moves through the internetwork, its physical address changes, but its protocol address remains same . </P>

Difference between layer2 and layer 3 switch wiki