Compatible Systems 5.4 - Manual (Page 288)

282 Appendices
Each group of devices is assigned a unique “network number” which repre-
sents that particular group to all of the routers on the network. Packets which
are sent between members of the same group are simply sent directly from
one member to another.
Packets which must go between devices belonging to two different groups
travel through routers, which forward them along an optimal path.
By examining the destination network number in a packet that must be
forwarded, and by using information that routers automatically pass between
themselves in IPX Routing Information Protocol (RIP) packets, any router
can determine the optimal path for forwarding packets from one group to
another.
This scheme relies on the fact that each segment is assigned a unique network
number. If not, the routers have no way of knowing which of the physical
segments with that number should actually receive a packet.
IPX Routing Example
Among routable network protocols, IPX is relatively simple. Each physical
network segment is assigned a network number by the routers on the segment.
The network number can be in the range of 1 to FFFFFFFE (that’s 8 hexadec-
imal digits). In the diagram above, 100 and 10C01 are the network numbers
for the two segments shown.
Establishing the network number for an IPX network segment is referred to
as “seeding” the network. You should generally only have one seed router per
Backbone Local Net
Router
Workstation
Workstation
Net: 100
Net: 10C01