Using The Set Dhcp Relay Agent Sub-Option Command To Enable Option 82 Suboption Support - Juniper JUNOSE SOFTWARE 11.0.X - BROADBAND ACCESS CONFIGURATION GUIDE 4-1-2010 Configuration Manual

| | | | L2 Circuit ID type: 1
| | | JUNOSe data len: 9 bytes
| | JUNOSe IANA: 13 0a
| subopt 9 len: 14 bytes
subopt code: 9
Using the set dhcp relay agent sub-option Command to Enable Option 82
Suboption Support
NOTE: We recommend that you use the set dhcp relay agent sub-option command
for new option 82 suboption configurations. However, JUNOSe software continues
to support the set dhcp relay agent command, with option 82 suboptions, to provide
backward-compatibility for existing scripts.
You use the set dhcp relay agent sub-option command to enable support for a
specific DHCP relay agent option 82 suboption Agent Circuit ID (suboption 1), Agent
Remote ID (suboption 2), and Vendor-Specific (suboption 9). When you issue this
command, the router adds DHCP relay agent information suboption 1 to every packet
it relays from a DHCP client to a DHCP server. The Agent Circuit ID suboption
identifies the interface on which DHCP packets are received. When the packets are
received on a LAG interface, the router clearly identifies the interface.
The suboptions include information from the DHCP relay agent that the DHCP server
can use to implement parameter assignment policies. The DHCP server echoes the
suboptions when it replies to the DHCP client, but the DHCP relay strips the
suboptions before relaying the packets to the client.
The Agent Circuit ID suboption identifies the interface on which the DHCP packets
are received. This suboption contains the following information, based on interface
type:
ATM interface
[<hostname>|<vrname>:]<interface type> <slot>/<port>[.<sub-if>]:<vpi>.<vci>
Examples:
atm 4/1.2:0.101
relayVr:atm 4/1:0.101
bostonHost:atm 4/1.2:0.101
Ethernet interface
[<hostname>|<vrname>:]<interface type> <slot>/<port>
Examples:
fastEthernet 1/2
relayVr:fastEthernet 1/2
bostonHost:fastEthernet 1/2
Ethernet interface with VLAN
Chapter 20: Configuring DHCP Relay
Configuring DHCP Relay and BOOTP Relay
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