address.
the address range, if extended addressing is being used. The machine then
selects a random node address and issues an AARP (AppleTalk Address Res-
olution Protocol) to see if anyone is using that particular network node
address. If there's no response, the machine continues using that address.
Node addressing is completely dynamic and requires no administration.
between 65,280 and 65,534 at random. This range is referred to as the star-
tup range. The node number is also chosen at random. If the node was
started before, it uses its previous address as a hint. In either case, the node
uses AARP to check whether the selected provisional address is in use. If the
address is in use, it selects another node number and checks again. If the node
is using a hint and subsequently exhausts all available node numbers without
finding an unused address, it chooses a new network address from the star-
tup range and a new node number, and then repeats the check for an unused
address.
range. If the network number for the provisional address falls between the
segment's cable range, the address is kept. Otherwise, a new network num-
ber is chosen from this cable range, and the resulting node address is checked
by using AARP. If the address is in use, the node selects another node num-
ber. If it runs out of node numbers, it chooses another network number from
within the segment's cable range and repeats the node-address check process.
Once the node finds an unused network number and node number combi-
nation, it becomes its final node address. The address is saved and used as a
future hint.
Address Resolution Protocol (AARP), makes up the OSI Layer 3 equivalent.
DDP is responsible for connectivity to the upper-layer protocols, whereas
AARP is charged with connectivity to the lower layers.