Each network needs to able to uniquely address each node on a network, this network layer node address may be the same as, or independent of, the already unique data link layer address.
Once a packet has been routed to the correct network (data link), based on the network number, it must be delivered to the correct node. delivery of the packet on a network is done using the layer 2 (data link layer) address. A companion protocol is called of layer 3 node address to the layer 2 data link address. this companion protocol is called the address Resolution Protocol (ARP) for IP and AppleTalk address Resolution Protocol (AARP) for AppleTalk. IP and AppleTalk both use ARPs but IPX does not. because the IPX 48-bit node Address is always the same as the 48-bit data link address. the ARP must be working correctly in order to maintain connectivity between the devices in an internetwork.
Tidak ada komentar:
Posting Komentar