Configuring The Dhcp Server Security Functions - 3Com MSR 50 Series Configuration Manual

582 C 33: DHCP S
HAPTER
Configuring the DHCP
Server Security
Functions
C
ERVER ONFIGURATION
Define existing DHCP options. Some options have no unified definitions in RFC
■
2132; however, vendors can define such options as Option 43 as needed. The
self-defined DHCP option enables DHCP clients to obtain vendor-specific
information.
Expand existing DHCP options. When the current DHCP options cannot meet
■
the customer's requirements (for example, you cannot use the dns-list
command to configure more than eight DNS server addresses), you can expand
these options.
To configure a self-defined DHCP option in the DHCP address pool, use the
following commands:
To do...
Enter system view
Enter DHCP address pool
view
Configure a self-defined
DHCP option
Table 33 Description of common options
Option
3
6
15
44
46
51
58
59
66
67
43
c
CAUTION:
Be careful when configuring self-defined DHCP options because the
■
configuration of these options may affect the DHCP operation process.
When you use self-defined option (Option 51) to configure the IP address lease
■
duration, convert the lease duration into seconds in hexadecimal notation.
This configuration is necessary to secure DHCP services on the DHCP server.
Use the command...
system-view
dhcp server ip-pool pool-name
option code { ascii ascii-string | hex
hex-string&<1-16> | ip-address
ip-address&<1-8> }
Name
Router Option
Domain Name Server Option
Domain Name
NetBIOS over TCP/IP Name Server
Option
NetBIOS over TCP/IP Node Type
Option
IP Address Lease Time
Renewal (T1) Time Value
Rebinding (T2) Time Value
TFTP server name
Bootfile name
Vendor Specific Information
Remarks
-
-
Required
No DHCP option is
configured by default
Corresponding
command Parameter
gateway-list ip-address
dns-list ip-address
domain-name ascii
nbns-list ip-address
netbios-type hex
expired hex
expired hex
expired hex
tftp-server ascii
bootfile-name ascii
- hex