Protocols And Standards - HP A5120 EI Series Configuration Manual

Figure 21 Sub-option 2 in normal padding format
0
Sub-option type (0x02)
Verbose padding format
2.
Sub-option 1: Padded with the user-specified access node identifier (ID of the switch that adds

Option 82 in DHCP messages), and the type, number, and VLAN ID of the interface that received
the client's request. See
Figure 22 Sub-option 1 in verbose padding format
Sub-option type (0x01)
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
Sub-option 2: Padded with the MAC address of the DHCP relay agent interface or the MAC address

of the DHCP snooping switch that received the client's request. It has the same format as that in
normal padding format. See
Option 184
Option 184 is a reserved option, and parameters in the option can be defined as needed. The switch
supports Option 184 carrying the 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. DHCP clients contact the backup

when the primary is unreachable.
Sub-option 3: Voice VLAN ID and the result whether or not DHCP clients take this ID as the voice

VLAN.
Sub-option 4: Failover route that specifies the destination IP address and the called number. A

Session Initiation Protocol (SIP) user uses this IP address and number to reach another SIP user when
both the primary and backup calling processors are unreachable.
NOTE:
You must define sub-option 1 to make other sub-options effective.

Protocols and standards

RFC 2131, Dynamic Host Configuration Protocol

7
Length (0x08)
MAC Address
Figure 22.
Length
Interface type
VLAN ID
Figure 22.
Figure
15 23
Remote ID type (0x00)
Node identifier
Interface number
21.
28
31
Length (0x06)