H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 30)

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Figure 14 Sub-option 2 in normal padding format
2. Verbose padding format
• Sub-option 1: Padded with the user-specified access node identifier (ID of the device that adds
Option 82 in DHCP messages), and the type, number, and VLAN ID of the interface that received
the client’s request.
Figure 15 Sub-option 1 in verbose padding format
NOTE:
The VLAN ID field has a fixed length of 2 bytes. All the other padding contents of sub-option 1 are length
variable. See
Figure 15 .
• Sub-option 2: Padded with the MAC address of the DHCP relay agent interface or the MAC
address of the DHCP snooping device that received the client’s request. It has the same format as
that in normal padding format. See Figure 14 .
Option 184
Option 184 is a reserved option, and parameters in the option can be defined as needed. The device
supports Option 184 carrying voice related parameters, so a DHCP client with voice functions can get an
IP address along with specified voice parameters from the DHCP server.
Option 184 involves the following sub-options:
• Sub-option 1: IP address of the primary network calling processor, which serves as the network
calling control source and provides program downloads.
• Sub-option 2: IP address of the backup network calling processor that DHCP clients will contact
when the primary one is unreachable.
• Sub-option 3: Voice VLAN ID and the result whether DHCP clients take this ID as the voice VLAN or
not.
• Sub-option 4: Failover route that specifies the destination IP address and the called number that a
Session Initiation Protocol (SIP) user uses to reach another SIP user when both the primary and
backup calling processors are unreachable.
NOTE:
For Option 184, you must define sub-option 1 to make other sub-options take effect.