Configuration Example-Using Dhcp Relay Option 82 To Pass Ieee 802.1P Values To Dhcp Servers; Figure 13: Passing 802.1P Values To The Dhcp Server - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - BROADBAND ACCESS CONFIGURATION GUIDE 2010-10-12 Configuration Manual

Figure 13: Passing 802.1p Values to the DHCP Server

DHCP client
Sends DHCP packet
with assigned 802.1p
Copyright © 2010, Juniper Networks, Inc.
Configuration Example—Using DHCP Relay Option 82 to Pass IEEE 802.1p Values
to DHCP Servers
Using the DHCP relay agent option 82 feature, you can configure an environment in which
a customized DHCP server assigns an IP address that provides the desired service to the
DHCP client.
The DHCP server uses information based on the IEEE 802.1p values, which are extracted
from the DHCP packets using JunosE Software layer 2 policies, to determine the
appropriate IP address to assign to the client.
This type of environment, which is illustrated in Figure 13 on page 509, includes the following
components:
Layer 2 policy on the ingress interface (that is, the interface that receives the client's
DHCP packet) that maps the 802.1p value from the packet to a user packet class
(UPC.)
NOTE: To ensure optimal performance when mapping 802.1p values to
UPCs, order the classifier groups in the VLAN policy list with the most often
used UPC values listed first.
DHCP relay agent option 82 configuration that enables Vendor-Specific suboption
type 2 (User Packet Class) support and maps the Layer 2 policy user packet class to
the option 82 user packet class suboption.
Customized DHCP server configuration that assigns IP addresses based on the option
82 user packet class suboption. The IP address is associated with the appropriate
quality, type, or class of service for the user packet class specified in the option 82
suboption.
DHCP relay
Ingress VLAN policy Relay Agent copies
maps 802.1p UPC into option 82
(user priority) to UPC vendor-specific suboption
The following example describes a sample procedure that creates an environment that
passes 802.1p values to the DHCP server, which then assigns an IP address that enables
the desired service to the DHCP client.
Configure a layer 2 policy that maps 802.1p values to user packet class values for a
1.
VLAN interface.
host1(config)# vlan classifier-list dot1p0 user-priority 0
host1(config)# vlan classifier-list dot1p1 user-priority 1
host1(config)# vlan classifier-list dot1p2 user-priority 2
host1(config)# vlan classifier-list dot1p3 user-priority 3
host1(config)# vlan classifier-list dot1p4 user-priority 4
Chapter 20: Configuring DHCP Relay
DHCP server
Uses UPC in option 82
vendor-specific suboption
to determine the IP address
that grants the desired service
509