Which statement accurately describes the function of a subnet mask and what 255.255.255.0 indicates?

Which statement accurately describes the function of a subnet mask and what 255.255.255.0 indicates?

• A. It designates the next-hop router used to reach networks outside the local subnet.
• B. It identifies which part is the network vs the host; 255.255.255.0 means the first 24 bits are network and the last 8 bits are host.
• C. It controls wireless encryption standards.
• D. It specifies DNS server addresses for the host.

Answer: (B)

Subnet masks define which portion of an IPv4 address identifies the network and which portion identifies the host within that network. The value 255.255.255.0 uses 1s in the first three octets and 0s in the last octet, which in binary is 11111111.11111111.11111111.00000000. The ones designate the network portion, so the first 24 bits are the network, and the last 8 bits are the host inside that network. This arrangement lets devices determine whether a destination is on the same local network or if traffic should be sent to a gateway for routing. It’s also expressed as /24 in CIDR notation, highlighting that 24 bits are used for the network part. This mask isn’t about choosing a next-hop router, encryption standards, or DNS servers. Those functions come from routing tables, security settings, and DNS configuration, respectively.

Subnet masks define which portion of an IPv4 address identifies the network and which portion identifies the host within that network. The value 255.255.255.0 uses 1s in the first three octets and 0s in the last octet, which in binary is 11111111.11111111.11111111.00000000. The ones designate the network portion, so the first 24 bits are the network, and the last 8 bits are the host inside that network. This arrangement lets devices determine whether a destination is on the same local network or if traffic should be sent to a gateway for routing. It’s also expressed as /24 in CIDR notation, highlighting that 24 bits are used for the network part.

This mask isn’t about choosing a next-hop router, encryption standards, or DNS servers. Those functions come from routing tables, security settings, and DNS configuration, respectively.