DHCP

Question 1

What does the DHCP Offer / ACK Include?

Answer 1

• Unique IP Address for Client
• Netmask for local network
• Lease Time
• Routing Information (default gateway)
• Host name, domain name (optional)
• Name (DNS) server (optional)

Question 2

What are the DHCP Steps?

Answer 2

1) DHCP Discover: Client asks server for an IP address
2) DCHP Offer: Server provides a possible IP address to client
3) DHCP Request: Client accepts the offer and requests to be assigned the IP address
4) DHCP ACK: Server acknowledges request and assigns new IP address to client
5) DHCP Release

Question 3

What happens if a client receives two DHCP offers?

Answer 3

The offer with the longer lease time is requested.

Question 4

What happens when the DHCP lease runs out?

Answer 4

Client sends a new DHCP request when half the lease is left.
If no response, repeat again when one eighth of the lease is left.
This message is unicast, not broadcast.

Question 5

What protocol is DHCP built on?

Answer 5

UDP (ports 67 for server, 68 for client)