Technical data

Configuring the DHCP Server
7.8 Supporting Utilities
$ DHCPDBDUMP
01:08:00:2b:e5:2c:44|0|7|10.10.2.100|949084208|949085408|949084808|949084208|
10.10.2.6|sarek12|compaq.com|
01:08:00:2b:bf:7d:bb|0|7|10.10.2.101|949084349|949085549|949084949|949084349|
10.10.2.6|gody|compaq.com|
01:08:00:2b:e5:2c:44|0|7|10.10.4.100|948463
7.8.2 Using the DHCPDBMOD Utility
The DHCPDBMOD command modifies the lease and naming information in the
database files. It allows the user to create, delete, or modify existing database
entries and to preassign static IP address to clients.
The utility takes input from a file that describes various entries in the database.
The syntax of each entry is similar to the output of
DHCPDBDUMP .
Use the following format:
• Terminate each record to be loaded by a new line.
• Delimit the fields within each record with the vertical bar (|) character.
• Express date fields in one of the following ways:
– Coordinated Universal Time (UTC), the number of seconds since 00:00
01/01/1970 GMT
– A format more easily understood, such as Mon Jan 09 1995 10:00 or
01/09/1995 10:00:00
Example 7–11 shows a sample entry. The first entry describes the client called
alpha.acme.com with the IP address 143.32.3.20.
The second entry describes a Microsoft DHCP client with the IP address
143.32.3.21. No name is given for this client.
Example 7–11 Sample DHCPDBMOD Entry
$ DHCPDBMOD
00:a0:24:8c:6b:09
1
|1
2
|6
3
|143.32.3.20
4
|844989457
5
|844989466
6
|844989466
7
|844989466
8
|143.32.3.1
9
|alpha
10
|acme.com
11
|
01:00:40:05:14:df:11|0|7|143.32.3.21|844989457|844989466|844989466|844989466
|143.32.3.1|||
Although some fields can be empty, each entry consists of the following fields:
1
MAC address
2
MAC address type
3
MAC address length (octets)
4
IP address
5
Start of lease (UTC)
6
Lease expiration (UTC)—use -1 to indicate an infinite lease
7
Time when lease can be extended (UTC)
8
Time when host last renewed or acquired this lease (UTC)
9
IP address of server owning the lease
7–64 Configuring the DHCP Server