5 dynamic host configuration protocol -46, 5 dynamic host configuration protocol – Hitachi Koki USA DDC 35n User Manual
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6.5 Dynamic Host Configuration Protocol
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6.5 Dynamic Host Configuration Protocol
DHCP is a service much like bootp that provides a method for 
assignment and maintenance of IP addresses. The NIC is able to obtain 
IP information from this service.
There are two user settable variables related to the DHCP function. 
These are accessible in the TCP section of Network Administration, in 
the HTML pages.
1.
DHCP enable; and
2.
Use IP info in NVRAM
a. If DHCP is not enabled, the NIC sends no DHCP requests under
any circumstances. If the NIC does not have an IP address stored, 
or if “Use IP info in NVRAM” is OFF, the NIC issues BOOTP 
requests, etc.
b. If DHCP is enabled, the NIC sends DHCP requests when the NIC
is reset or on power up, provided that the NIC does not have an IP 
address stored, or that “Use IP info in NVRAM” is OFF. If the IP 
address cannot be obtained by DHCP, an attempt to obtain the IP 
address using BOOTP and RARP is made.
c. If DHCP is enabled, and the NIC had an IP address in NVRAM,
and “Use IP info in NVRAM” is ON, then the NIC uses the IP 
information from NVRAM and there is no DHCP activity on the 
part of the NIC.
The factory default is with both DHCP enable ON and Use IP info in 
NVRAM ON. In this case, the NIC issues DHCP requests if it does not 
already have IP identification information stored in its NVRAM.
Important!
• If DHCP and the NIC is in the default mode (“Use IP info in
NVRAM”= ON), you must establish a
permanent lease
or reserva-
tion for the NIC in the DHCP server. Failure to do this may cause the 
same address to be given out to another host.