Technical data

Configuring the DHCP Server
7.5 Using DHCP GUI to Configure DHCP
Canonical Name
Overrides the value normally returned by a
gethostname routine call (default).
Primarily used for multihomed hosts with a canonical name corresponding to an
interface that is not recognized by DHCP (for example, ATM interfaces) and for
high-availability servers that have per-service IP addresses that differ from a
physical IP host address. The following are valid values:
False: Use the host name returned by a gethostname routine call. Default.
True: Use the specified canonical host name.
Check BOOTP Client Net
Before a BOOTP client is given a hard-wired IP address, the server makes sure
that the client is connected to the logical IP network for which the address is
valid. If the client is not connected, the server logs an error and does not send a
response to the client.
For this to work properly, the NETMASKS. file must contain the network
numbers and masks for any nonstandard IP Class A, B, or C configuration.
The following are valid values:
False: Do not check the IP network of the address. Default.
True: Check the IP network of the address.
DNS expiration tracks DHCP lease
This parameter implies that SIG resource records for DNS are updated with
expiration times that match the DHCP client’s lease time. If a client sends a
‘‘DHCP release’’, the lease is prematurely expired and the SIG record is marked
as expired. In order to reduce the amount of traffic between DHCP and DNS, the
default value is False.
This policy affects only installations that use the Dynamic DNS option.
Default Lease Time
Specifies the value used on all leases for clients that have no other value explicitly
configured. Enter the lease time of the IP address granted to a client.
The default lease time is one day.
Expand BOOTP Packet
Expands the BOOTP reply packet to 548 bytes. Applies to BOOTP clients only.
The following are valid values:
False: All replies to BOOTP clients are 300 octets or a size equal to the size of the
packet received, whichever is larger. Default.
True: All replies to BOOTP clients are expanded to 548 bytes.
Force Broadcast Reply
The DHCP server generally sends unicast reply packets in response to client
packets. This toggle tells the server to send broadcast reply packets instead of
unicast reply packets. The following are valid values:
False: Forces the DHCP server to use unicast reply packets. Default.
True: Forces DHCP server to broadcast reply packets to the client, even when the
server could use unicast replies.
7–28 Configuring the DHCP Server