What is the last usable IP address in the 218.6.0.0/17 network?

The correct answer is C. 218.6.127.254. For the 218.6.0.0/17 network, the network mask extends into the second octet, defining the network and broadcast addresses. Calculating the broadcast address and then subtracting one yields the last usable IP.

Routing Fundamentals

Question

Options

A218.6.125.254
B218.6.126.254
C218.6.127.254
D218.6.128.254

How the community answered

(45 responses)

A
4% (2)
B
13% (6)
C
76% (34)
D
7% (3)

Why each option

For the 218.6.0.0/17 network, the network mask extends into the second octet, defining the network and broadcast addresses. Calculating the broadcast address and then subtracting one yields the last usable IP.

A218.6.125.254

This is within the network but not the last usable IP.

B218.6.126.254

This is within the network but not the last usable IP.

C218.6.127.254Correct

A /17 subnet mask is 255.255.128.0. The network 218.6.0.0/17 means the third octet's range for this block is from 0 to 127. The broadcast address for this block is 218.6.127.255, and the last usable IP address is one less than the broadcast, which is 218.6.127.254.

D218.6.128.254

This address is outside the 218.6.0.0/17 network, as it falls into the next /17 block (218.6.128.0/17).

Concept tested: Subnetting - last usable IP

Topics

#subnetting#IPv4 addressing#network calculation#CIDR

Community Discussion

No community discussion yet for this question.

Full JN0-102 Practice