What is the largest IPv4 network prefix you can define within DHCP?

• A. /1
• B. /0
• C. /32
• D. /128

Answer: (A)

In IPv4, the prefix length decides how much of the address space is treated as the network versus the hosts. DHCP scopes must live inside a defined subnet, so the largest subdivision you can practically define for an address pool in IPv4 is a /1. A /1 covers half the IPv4 space, giving a valid, bounded network for the DHCP pool, whereas a /0 would blanket the entire address space and isn’t allowed in this context. A /32 represents a single host and is far too small for a typical DHCP scope, and a /128 is an IPv6 notation, not IPv4. So the largest IPv4 prefix you can define in this DHCP scenario is /1.