Manualsbrain.com
  1. Manuels
  2. Marques
  3. 3com
  4. S7906E
  5. Manuel De Montage

3com S7906E Manuel De Montage

Télécharger
Page de 2621
 
1-5 
z 
Option 121: Classless route option. It specifies a list of classless static routes (the destination 
addresses in these static routes are classless) that the requesting client should add to its routing 
table. 
z 
Option 33: Static route option. It specifies a list of classful static routes (the destination addresses 
in these static routes are classful) that a client should add to its routing table. If Option 121 exists, 
Option 33 is ignored. 
For more information about DHCP options, refer to RFC 2132. 
Self-Defined Options 
Some options, such as Option 43, have no unified definitions in RFC 2132. The formats of some 
self-defined options are introduced as follows. 
Vendor-specific option (Option 43) 
DHCP servers and clients exchange vendor-specific information through messages containing the 
vendor-specific option (Option 43). Upon receiving a DHCP message requesting Option 43 (in Option 
55), the DHCP server returns a response message containing Option 43 to assign vendor-specific 
information to the DHCP client. 
The DHCP client can obtain the following information through Option 43: 
z 
Auto-Configuration Server (ACS) parameters, including the ACS URL, username, and password. 
z 
Service provider identifier acquired by the customer premises equipment (CPE) from the DHCP 
server and sent to the ACS for selecting vender-specific configurations and parameters. 
z 
Preboot Execution Environment (PXE) server address for further obtaining the bootfile or other 
control information from the PXE server. 
1)  Format of Option 43 
Figure 1-5 Format of Option 43 
 
 
For the sake of scalability, network configuration parameters are carried in different sub-options of 
Option 43 so that the DHCP client can obtain more information through Option 43 as shown in 
. The sub-option fields are described as follows: 
z 
Sub-option type: Type of a sub-option. The field value can be 0x01, 0x02, or 0x80. 0x01 indicates 
an ACS parameter sub-option. 0x02 indicates a service provider identifier sub-option. 0x80 
indicates a PXE server address sub-option. 
z 
Sub-option length: Length of a sub-option excluding the sub-option type and sub-option length 
fields. 
z 
Sub-option value: Value of a sub-option. 
2)  Format of the sub-option value field of Option 43 
z 
, the value field of the ACS parameter sub-option is filled in with variable 
ACS URL, username, and password separated with a space (0x20) in between.