Ccna routing and Switching Complete Study Guide

The subnets (do this first)

0

64

128

192

Our first host (perform host addressing last)

1

65

129

193

Our last host

62

126

190

254

The broadcast address (do this second)

63

127

191

255

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Subnetting Basics 

147

Again, before getting into the next example, you can see that we can now subnet a 

/26 as long as we can count in increments of 64. And what are you going to do with this 

fascinating information? Implement it! We’ll use Figure 4.4 to practice a /26 network 

implementation.

f i g u r E   4 . 4     Implementing a class C /26 (with three networks)

192.168.10.64

192.168.10.128

.129

.1

.65

Router#show ip route

 [output cut]

C 192.168.10.0 is directly connected to Ethernet 0

C 192.168.10.64 is directly connected to Ethernet 1

C 192.168.10.128 is directly connected to Ethernet 2

.68

.67

.66

.132

.131

.130

192.168.10.0

.3

.2

.5

.4

The /26 mask provides four subnetworks, and we need a subnet for each router inter-

face. With this mask, in this example, we actually have room with a spare subnet to add to 

another router interface in the future. Always plan for growth if possible!