What is the default time-to-live (TTL) value for a leased IP address?

What is the default time-to-live (TTL) value for a leased IP address?

• A. Three Days
• B. One Day
• C. One Hour
• D. Seven Days

Answer: (A)

DHCP lease time defines how long an IP address is assigned to a client. The default value is chosen to balance keeping addresses available in the pool with not forcing devices to renegotiate too often. Three days is a common default because it provides a reasonable period for typical devices to operate without constant renewal, while still freeing up addresses in a timely way if a device leaves or is turned off. Renewal behavior helps explain why this works: a client typically tries to renew at about 50% of the lease duration. If the device moves networks or stays connected, it can refresh the lease; if it drops off the network, the address will eventually return to the pool after the lease expires. Shorter durations (like one hour) would increase DHCP traffic and churn, while longer ones (like seven days) can reduce address availability in busy networks. A one-day default is less common in many setups, though it can be used in certain environments. Note: TTL in IP headers is a separate concept from DHCP lease time; they serve different purposes.

DHCP lease time defines how long an IP address is assigned to a client. The default value is chosen to balance keeping addresses available in the pool with not forcing devices to renegotiate too often. Three days is a common default because it provides a reasonable period for typical devices to operate without constant renewal, while still freeing up addresses in a timely way if a device leaves or is turned off.

Renewal behavior helps explain why this works: a client typically tries to renew at about 50% of the lease duration. If the device moves networks or stays connected, it can refresh the lease; if it drops off the network, the address will eventually return to the pool after the lease expires. Shorter durations (like one hour) would increase DHCP traffic and churn, while longer ones (like seven days) can reduce address availability in busy networks. A one-day default is less common in many setups, though it can be used in certain environments.

Note: TTL in IP headers is a separate concept from DHCP lease time; they serve different purposes.