Appletalk Protocol - Netopia R5100 User Reference Manual

11-2 User's Reference Guide
If the cabling of your network were a street system, then a node address would correspond to a building's
street address. But node addresses are not permanent. Each AppleTalk device determines its node address at
startup. Although a Macintosh that is starting up will try to use its previous address, the address will often be
different upon restart. This dynamic node addressing scheme prevents conflicts when devices are moved
between networks and simplifies the administrative tasks of a network. If you have only one network, the node
address alone is all the information AppleTalk needs to send a packet from one computer to another.
However, networks can be connected together through routers, such as the Netopia R5000 Series, into an
internetwork (often shortened to internet). Because devices on different networks can have duplicate node
numbers, AppleTalk tells them apart according to an additional part of their addresses: the network number.
The Netopia R5000 Series assigns a unique network number to each member network. In terms of the city
street metaphor, the network number is similar to the name of the street. Putting a network number together
with a node number fully specifies the address of a node on an internet.
To make the services on an internet manageable, groups of devices on a network can be grouped into zones.
When this is done, selecting a network service (server, etc.) includes choosing a zone from which the service
can be selected. Like network numbers, zone names are assigned by routers.
A routing table is maintained by each AppleTalk router. The table serves as a map of the internet, specifying the
path and distance, in hops, between its router and other networks. The routing table is used to determine
whether a router will forward a data packet and, if so, to which network.
You can use the information in the AppleTalk routing table to observe and diagnose the Netopia R5000 Series
Router's current connections to other AppleTalk routers. To go to the AT Routing Table screen from the Netopia
R5000 Series Router's console, select Statistics & Logs from the Main Menu and then select AppleTalk
Routing Table. An AT Routing Table similar to the one shown below appears.
-Net---Range--Def Zone Name----------Hops-State-Next Rtr Addr.--Pkts Fwded
----------------------------------SCROLL UP--------------------------
1 --
2 --
3 --
4 --
5 --
6 --
7 --
8 --
10 --
11 --
12 --
16 --
*24 27
28 31
---------------------------------SCROLL DOWN-------------------------
UPDATE
'*' Entries have multiple zone names. Return/Enter on these to see zone list.
A router has multiple communications ports and is capable of forwarding information to other routers and
devices on the internet. The router performs packet forwarding, network and device address maintenance, and
other administrative functions required by the AppleTalk protocols.
AT Routing Table
Admin
AdMan
Aspirations
Sales
Marketing
Molluscs
Customer Service
Telemarketing
Rio
Regiment
Rhinos
Unique Services
Aspirations
Rhinos
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
2 Good 46.131
1 Good 46.131
1 Good 46.131
0
0
0
0
0
1
1
0
0
0
0
0
79
15