H3C Technologies H3C SecPath F1000-E - Manual (Page 177)

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{
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. 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 88 .
Figure 88 Sub-option 1 in verbose padding format
{
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 87 .
Option 184
Option 184 is a reserved option, and parameters in the option can be defined as needed. The firewall
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.
Protocols and standards
• RFC 2131, Dynamic Host Configuration Protocol
• RFC 2132, DHCP Options and BOOTP Vendor Extensions
• RFC 1542, Clarifications and Extensions for the Bootstrap Protocol
• RFC 3046, DHCP Relay Agent Information Option
• RFC 3442, The Classless Static Route Option for Dynamic Host Configuration Protocol (DHCP)
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