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Chapter 8 - IP Address and Network Configuration Vendor and Site Specific DHCP Options
154 Mediatrix 4104
Network Configuration
Table 93 lists some of the network options to configure in the DHCP server:
Vendor and Site Specific DHCP Options
This section briefly describes vendor and site specific DHCP options.
Most of the MIB variables described in “Services” on page 142 require that you define their IP address and, if
required, port number. When defining these variables, you can do so in two ways: via vendor specific options
or site specific options.
The default value is to use the vendor specific codes. In this case, the xxSiteSpecificCode MIB variables are
set to 0.
If you want to use site specific codes instead, change the value of the xxSiteSpecificCode MIB variables from
the default value (0) to the value you select in the DHCP server. See “Site specific code definition” on page 158
for an example of vendor specific and site specific settings.
Vendor Specific Options
The vendor specific DHCP option is a standard DHCP option used to store information specific to the vendor
of the DHCP client. The vendor specific option code is 43. Because there are different information elements
that can be stored in this option, each element has been allocated a “sub-option” number. See
Table 94 on
page 156 for the complete list.
Like all other options, the vendor specific information field (option 43) first contains a code (43), a length (in
byte) and some data that spans the number of bytes specified in the length.
The data is organized as a series of sub-options, each of them laid-out like a regular option (code, length,
data). The codes can be anything between 1 and 254, and the vendor, Media5, chooses these codes. See
Table 94 on page 156 for actual codes.
The following figures show the general and encapsulated layout of the vendor specific information option.
Figure 68: General Layout of a Vendor Specific Information Option
Figure 69: Layout for Encapsulated Vendor Specific Options
Figure 70 is an example of a vendor specific option containing an msHost IP address (192.168.1.2).
Table 93: Network Configuration
Information Description Option Data Format Example
Subnet Mask Specifies subnet configuration 001 xxx.xxx.xxx.xxx 255.255.255.0
Routers List of routers on your network 003 Array of IP Addresses 192.168.10.1
192.168.10.2
DNS Servers List of DNS servers on your network 006 Array of IP Addresses 192.168.10.11
192.168.10.12
Standards Supported RFC 2132 – DHCP Options and BOOTP Vendor Extensions, section 8.4
(“Vendor-specific options”)
43 Len Data Data Data Data …
43 Len Code1 Len1 Data1 Data1 … Code2 Len2 Data2 Data2 …