Specifications

TCP/IP Network Characteristics
8-26
BOOTP and DHCP Differences
DHCP is an extension of BOOTP; however, using a DHCP server to obtain IP
information differs from using a BOOTP server in the following ways:
DHCP Client Operation
During initialization, the access server acts as a DHCP client to obtain IP
configuration parameters (excluding the IP address; use a BOOTP server or the
DEFINE INTERNET ADDRESS command to configure the IP address). The access
server requests the following IP configuration parameters from a DHCP server:
• Default gateway
• Domain name
• Domain Name System (DNS) servers
• Windows Internet Naming Service (WINS) servers
Using a BOOTP Server Using a DHCP Server
The access server can learn its IP address
from a BOOTP server (or you can
configure it directly on the access server).
The access server does not learn its IP
address from a DHCP server. The access
server can learn the following from a
DHCP server:
• Domain name
• Default gateway
• Domain Name System (DNS)
servers
• Windows Internet Naming
Service (WINS) servers
You configure the IP information to be
learned in the BOOTP server’s database
and associate it with the access server’s
hardware address.
You do not configure the DHCP server
with any access server or client-specific
information. You need only to configure
the DECserver with network information
(for example, a domain name) and a pool
of IP addresses available for assignment.
The access server writes the information
it learns from the BOOTP server to
NVRAM.
The access server does not write the
information it learns from the DHCP
server to NVRAM. This ensures that the
access server receives the most recent
information from the DHCP server.