H3C Technologies H3C SecPath F1000-E - Manual (Page 175)

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the request, the DHCP server refers to the vendor-specific options table, and returns a response message
with Option 43 to assign the appropriate vendor-specific information to the DHCP client.
The DHCP client can obtain the following information through Option 43:
• Auto-Configuration Server (ACS) parameters, including the ACS URL, username, and password.
• Service provider identifier, which is acquired by the customer premises equipment (CPE) from the
DHCP server and sent to the ACS for selecting vender-specific configurations and parameters.
• Preboot Execution Environment (PXE) server address, which is used to obtain the bootfile or other
control information from the PXE server.
1. Format of Option 43
Figure 83 Format of Option 43
Network configuration parameters are carried in different sub-options of Option 43 as shown
in
Figure 83 . The sub-option fields are described as follows:
{
Sub-option type—Type of a sub-option. The field value can be 0x01 (an ACS parameter
sub-option), 0x02 (a service provider identifier sub-option), or 0x80 (a PXE server address
sub-option).
{
Sub-option length—Length of a sub-option excluding the sub-option type and sub-option length
fields.
{
Sub-option value—Value of a sub-option. The value format varies with sub-options.
2. Format of the sub-option value field of Option 43
{
As shown in Figure 84 , the value field of the ACS parameter sub-option contains variable ACS
URL, username, and password separated by spaces (0x20).
Figure 84 Format of the value field of the ACS parameter sub-option
{
The value field of the service provider identifier sub-option contains the service provider
identifier.
{
Figure 85 shows the format of the value field of the PXE server address sub-option. The value of
the PXE server type can only be 0. The server number field indicates the number of PXE servers
contained in the sub-option. The server IP addresses field contains the IP addresses of the PXE
servers.