Technical data

Configuring the DHCP Server
7.5 Using DHCP GUI to Configure DHCP
Auto Synchronize Database
Choose True to flush the server database to disk after each update. This
makes the server more reliable if there is a failure such as a system crash or
unintentional power shutdown. Setting this parameter to True can slow down the
server.
The default is False.
BOOTP Addr From Pool
Specifies whether the DHCP server does not require a preestablished binding for
BOOTP clients. When none exists, the server allocates an address from the pool
to the client. Because BOOTP does not understand the concept of lease times, all
such allocations are permanent regardless of the lease times specified elsewhere
in the database.
When you disable BOOTP Addr From Pool, the Server only supports BOOTP
clients whose IP address is configured into the database. This means the binding
of the IP address to the client must be preestablished. The address must be
consistent with the network to which the client is attached. See Section 7.6 for
information on how to preestablish a binding between a MAC address and an IP
address. The following are valid values:
False: Do not pick an address from a pool. Requires a preestablished binding. Default.
True: Pick an address from a pool. Does not require a preestablished binding.
BOOTP Client Lease Extension
TCP/IP Services does not currently support this parameter.
When you set this parameter to a value above zero, the server grants Finite
leases to BOOTP clients. BOOTP clients do not know this, so before the server
can reuse these leases, it must ping the IP address. If the server hears a reply, it
extends the lease by the time interval (in seconds) specified by this parameter.
The default value is 0 seconds.
BOOTP Compatibility
DHCP can serve BOOTP clients as well as DHCP clients. The following are valid
values:
False: The server should act as a DHCP server only.
True: The server should also act as a BOOTP server. Default.
Bootfile not sent as option
Because the DHCP clients normally do not require bootfile names, the space
reserved for this purpose (the ‘‘file’’ field) in reply packets is used by JOIN as
an extension of the DHCP options field. This arrangement permits the client
to receive more configuration information than would otherwise be possible in a
standard-sized DHCP packet.
Enabling this parameter sends the bootfile name in the ‘‘file’’ field, instead of
as a DHCP option. Certain network computers (NCs) expect to find the bootfile
information in the ‘‘file’’ field and will not successfully load their OS images
unless this parameter is set to True. Note: BOOTP clients always receive a
bootfile name in the ‘‘file’’ field, regardless of the state of this option.
Configuring the DHCP Server 7–27