User manual

B-6 Addressing Scheme

Supernetting (Advanced TCP/IP)

Because Class B Internet addresses are in short supply, larger

networks are now usually granted a contiguous block of several

Class C addresses. Unfortunately, this creates very large

routing tables since multiple Class C routes have to be defined

for each network containing more than 254 nodes. Larger

routing tables mean more work for the routers and, therefore,

poorer performance.

With traditional IP, each class C network must have a routing

table entry, as shown in Figure 2 below.

Figure 2. Sample Class C Routing topology