A network engineer is configuring a point-to-point WAN link between two branch routers usi… — Cisco CCNA

A network engineer is configuring a point-to-point WAN link between two branch routers using the $192.168.10.4/30$ network segment. Which IPv4 address represents a valid usable host address for one of the router interfaces?

A
$192.168.10.4$
$192.168.10.5$ Answer
C
$192.168.10.7$
D
$172.32.10.5$

Answer

The address

192.168.10.5

is a valid usable host IPv4 address in the

192.168.10.4/30

subnet.

In a

/30

subnet starting at

192.168.10.4

, the total block size is

4

IP addresses (

192.168.10.4

through

192.168.10.7

). The network address is

192.168.10.4

and the broadcast address is

192.168.10.7

. The valid usable host IP addresses for router interfaces are

192.168.10.5

and

192.168.10.6

. Therefore,

192.168.10.5

is a correct host address.

Step-by-Step Solution

Determine the block size for a

/30

prefix length.

/30

mask uses

30

network bits and

2

host bits (

32 - 30 = 2

). The block size is

2^2 = 4

Calculating the block size defines the size and boundaries of the subnet segment.

Identify the network address and broadcast address for the segment.

For the network starting at

192.168.10.4

, the block ends before

192.168.10.8

. The network address is

192.168.10.4

and the broadcast address is

192.168.10.7

The first address in the block is reserved for the network ID and the last address is reserved for broadcast.

Determine the range of valid usable host IP addresses.

Usable host addresses span from

192.168.10.5

through

192.168.10.6

Usable host addresses are the IP addresses strictly between the network ID and the broadcast address.

Key Concept

IPv4 Subnet Boundaries and Usable Host Address Ranges

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic