If the first three octets of an IPv4 address are the same under a /24 subnet mask, what does this indicate?

If the first three octets of an IPv4 address are the same under a /24 subnet mask, what does this indicate?

• A. They are in the same network
• B. They are in different networks
• C. They require a router to communicate
• D. They are in the same broadcast domain

Answer: (A)

With a /24 mask, the network portion is the first three octets. If two addresses share identical first three octets under this mask, they belong to the same IPv4 network (same network ID). That means they can communicate directly on the local network without routing, provided they’re on the same Layer 2 segment. If they were in different networks, a router would be needed for communication.

With a /24 mask, the network portion is the first three octets. If two addresses share identical first three octets under this mask, they belong to the same IPv4 network (same network ID). That means they can communicate directly on the local network without routing, provided they’re on the same Layer 2 segment. If they were in different networks, a router would be needed for communication.