Installing and Administering Internet Services

256 Chapter6

Dynamic Host Conﬁguration Protocol (DHCP)

DHCP Components and Concepts

network. HP strongly recommends that you have only one DHCP server

on the network. If the client likes the offer, it sends a DHCPREQUEST

packet to the server. This indicates a formal request to lease the IP

address offered by the server.

NOTE The HP-UX client rejects offers for IP addresses with very short lease

times. For example, the client will reject an offer with a lease time of 10

seconds.

Step 4. The DHCP server receives the DHCPREQUEST packet and grants the

client its request to lease the IP address. The server sends a DHCPACK

to the client. This is the ofﬁcial notiﬁcation that the address has been

granted.

Step 5. Before the lease time expires, the DHCP client requests to extend the

lease by sending a DHCPREQUEST packet to the server. The server

then updates and extends the lease time. It sends a DHCPACK to the

client to notify it that the lease has been extended. These updates and

lease extensions continue as long as the client is powered on. If the lease

expires and the client is not powered on, and not able to request an

extension on the lease, the IP address is recycled.

Step 6. The DHCP server sends DHCPACK to extend the lease on the IP

address.

Figure 6-1 illustrates what takes place between the DHCP client and

server.