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VLSM error In ICND2 cert guide ?

Hi.I'm reading the VLSM chapter on the ICND2 cert guide.Specifically the section for adding a new subnet to an existing VLSM design.

In the book It says only the second , third and fifth possible /23 subnets will overlap.I don't understand why the fourth subnet 172.16.6.0         doesn't overlap with the R3 Lan 172.16.6.0.Is there something I'm missing?

Table 5-5

First Five Possible /23 Subnets

Subnet Subnet Number Subnet Broadcast Address

First (zero) 172.16.0.0 172.16.1.255

Second 172.16.2.0 172.16.3.255

Third 172.16.4.0 172.16.5.255

Fourth 172.16.6.0 172.16.7.255

Fifth 172.16.8.0 172.16.9.255

Table 5-6

Existing Subnet IDs and Broadcast Addresses from Figure 5-3

Subnet Subnet Number Subnet Broadcast Address

R1 LAN 172.16.2.0 172.16.3.255

R2 LAN 172.16.4.0 172.16.5.255

R3 LAN 172.16.6.0 172.16.6.255

R1-R2 serial 172.16.9.0 172.16.9.3

R1-R3 serial 172.16.9.4 172.16.9.7

1 REPLY
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VLSM error In ICND2 cert guide ?

hi,

from what you put here, i assume the free subnet is number FIVE, might be a typo or something.

plz Rate if it helped.

Soroush

Hope it Helps!

Soroush.
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