Technical data

Table 5–2: DHCP IP Address Allocation Methods
Method
Applicable Client
Description
Dynamic DHCP and BOOTP The DHCP server assigns an IP
address from an address pool to a client
for a specified amount of time (or until
the client explicitly relinquishes the
address). Addresses no longer needed
by clients can be reused.
Use dynamic allocation when:
• Clients will be connected to the
network only temporarily.
• You have a limited pool of IP
addresses that must be shared
among clients that do not need
permanent IP addresses.
• IP address are scare, and you need
to reclaim retired addresses so you
can assign them the new clients
being permanently connected to the
network.
For BOOTP clients, DHCP assigns
dynamic IP addresses from the address
pool and stores the addresses in the
lease database by assigning each lease
a time of infinity.
Static DHCP and BOOTP The system manager manually assigns
an IP address to a client and uses
DHCP to pass the assigned address to
the client.
Use static allocation in an error-prone
environment where it is desirable to
manage IP address assignment outside
of DHCP control.
Finite BOOTP-only The DHCP server assigns an IP
address from the pool to the BOOTP
client and defines a lease time based
on certain parameters you define in
the SERVER.PCY file. When the lease
expires, the DHCP server pings the IP
address. If the server receives a reply,
it extends the lease and does not offer
the address to a new client. If not, the
addressisfreeandcanbeassignedtoa
new client.
The typical network uses a combination of static and dynamic DHCP addressing.
As the local system manager or network administrator, you must decide which IP
addressing methods are appropriate for your specific policies and environment.
For detailed information about configuring the different types of addressing for
clients on your network, refer to the Compaq TCP/IP Services for OpenVMS
Management guide.
5–8 Network Server Services