Technical data
Configuring the DHCP Server
7.2 DHCP Server Components
Example 7–3 (Cont.) Sample NETS. File
# If there are fewer than three fields then the subnet and owner
# are implied by previous entries. The address range is specified
# as one or two IP addresses. If two then they must be separated
# by a dash "-", with no whitespace intervening. Multiple ranges
# may be specified for any owner. The IP addresses are checked for
# syntax, for uniqueness of ownership, and validity on the network
# specified. If the owner of a range is multi-homed, then the
# name used must be its canonical name (e.g. as echoed by hostname),
# or, if specified by address, the address must correspond to
# the canonical name as given in /etc/hosts
#
# For OpenVMS with DHCP configured on multiple cluster nodes (ie. DHCP
# cluster failover) enter 0.0.0.0 in the "owning" DHCP server field
# (field 2).
#
# Examples:
#192.1.1.32 192.1.1.34 192.1.1.35-192.1.1.43
#192.1.1.32 192.1.2.34 192.1.1.44-192.1.1.62
#192.1.1.64 192.1.2.34 192.1.1.66-192.1.1.94
#
# DHCP cluster failover example:
#192.1.1.64 0.0.0.0 192.1.1.66-192.1.1.94
#
10.10.2.0 0.0.0.0 10.10.2.100-10.10.2.110
10.10.4.0 0.0.0.0 10.10.4.100-10.10.4.110
The entries in the NETS. file shown in Example 7–4 describe the IP ranges for
two different networks, each with its own set of IP addresses.
Example 7–4 NETS Entries with IP Ranges for Two Networks
143.32.3.0 143.32.3.1 143.32.3.10-143.32.3.30 143.32.3.40-143.32.3.60
143.32.3.75-143.32.3.100
1
143.32.5.0 dhcpserver 143.32.5.10-143.32.5.200
2
In this example:
1
This entry comprises two lines and describes three noncontiguous ranges of
IP addresses for the network 143.32.3.0.
2
This entry describes a single range of addresses for the network 143.32.5.0.
Notice the use of an IP address in the first entry (143.32.3.1) and the use of
a host name (
dhcpserver
) in the second entry to describe the owner of the IP
address ranges.
7.2.2.4 Netmask Masks
If your network is subnetted in a format that is not consistent with the standard
class A, B, or C netmask address, you must include the network addresses and
netmasks in the NETMASKS. file during the initial DHCP server configuration.
Make sure you edit the NETMASKS. file and include an entry for each network.
Each entry in the file must include two fields: the network address and the
netmask address. Example 7–5 show a sample NETMASKS. file.
7–12 Configuring the DHCP Server