Juniper JUNOSE SOFTWARE 11.0.X - BROADBAND ACCESS CONFIGURATION GUIDE 4-1-2010 Configuration Manual page 542

JUNOSe 11.0.x Broadband Access Configuration Guide
The Agent Circuit ID suboption (suboption 1) and the Agent Remote ID suboption
(suboption 2) are typically determined by the client network access device and depend
on the network configuration. The Vendor-Specific suboption (suboption 9) is more
flexible and can be used by administrators to associate specific data with the DHCP
messages relayed between the DHCP relay and the DHCP server. For example the
Vendor-Specific suboption can include the client's IEEE 802.1p value, which identifies
the client's user priority.
NOTE: The DHCP relay agent replaces any existing Vendor-Specific value in the client
packet with the relay agent's value.
The JUNOSe software provides two commands that you can use to configure DHCP
relay agent information suboptions.
NOTE: The set dhcp relay agent command is a legacy command, which JUNOSe
software continues to support to provide backward-compatibility for existing scripts.
We recommend that all new configurations use the dhcp relay agent sub-option
command.
The set dhcp relay agent sub-option command enables you to manage specific
option 82 suboptions without impacting the configuration of other suboptions. The
legacy set dhcp relay agent command, however, changes the configuration of
suboptions in some cases.
Table 102 on page 503 indicates the effect each command has on enabling or disabling
relay agent information suboptions.
502
Configuring DHCP Relay and BOOTP Relay
Layer 2 Circuit ID (type 1) The hexadecimal representation of the layer 2
identifier in the Agent Circuit ID (suboption 1) value (for example, the ATM
VPI/VCI or Ethernet SVLAN/VLAN ID.) You can configure this suboption type
without the Agent Circuit ID.
User Packet Class (type 2) The hexadecimal representation of the user
packet class field, whose value is assigned by the layer 2 policy application.
The layer 2 policy application can be used to map the DHCP packet or
message IEEE 802.1p value to the user packet class field. See the JUNOSe
Policy Management Configuration Guide for information about layer 2 policies.
The set dhcp relay agent sub-option command Enables you to configure
option 82 to include any combination of the supported suboptions, including
the Vendor-Specific suboption.
The set dhcp relay agent command Enables you to configure option 82 to
include either or both the Agent Circuit ID suboption (suboption 1) and Agent
Remote ID suboption (suboption 2). The command does not support the
Vendor-Specific suboption (suboption 9).