Including Relay Agent Option Values In The Pppoe Remote Circuit Id - Juniper JUNOSE 11.1.X - BROADBAND ACCESS CONFIGURATION GUIDE 6-4-2010 Configuration Manual

commands similar to the following to create demultiplexer table entries and a subnet
route that points to the static subscriber interface.
In the example, the host routes are associated with the primary IP interface on Gigabit
Ethernet 1/0. Because the host routes are statically configured with the subscriber
interface, there is no need for the router to install DHCP host routes. Therefore, in
step 7, the set dhcp relay inhibit-access-route-creation command is used to prevent
DHCP relay from installing host routes.
1.
2.
3.
4.
5.
6.
7.
In the example, if you do not prevent DHCP relay from installing host routes, the
ARP spoof-checking mechanism associates the ARP traffic with the primary IP
interface (Gigabit Ethernet 1/0), although packets actually arrive on the subscriber
interface (ip53001), causing the router to detect a spoof and drop the packet.

Including Relay Agent Option Values in the PPPoE Remote Circuit ID

You can enable the router to capture and format a vendor-specific tag containing a
PPPoE remote circuit ID value transmitted from a digital subscriber line access
multiplexer (DSLAM) device. The router can then send this value to a Remote
Authentication Dial-In User Service (RADIUS) server or to a Layer 2 Tunneling Protocol
(L2TP) network server (LNS) to uniquely identify subscriber locations.
By default, the router formats the captured PPPoE remote circuit ID to include only
the agent-circuit-id suboption (suboption 1) of the DHCP relay agent information
Create a shared IP interface.
host1(config)#interface ip ip53001
Associate the shared IP interface with a static layer 2 interface.
host1(config-if)#ip share-interface gigabitEthernet 1/0
Make the shared interface an unnumbered interface.
host1(config-if)#ip unnumbered loopback 53
Specify the source addresses that the subscriber interface uses to demultiplex
traffic.
host1(config-if)#ip source-prefix 10.10.10.0 255.255.255.252
Exit Interface Configuration mode.
host1(config-if)#exit
Create a static route that sends traffic for destination address 10.10.10.0 to
subscriber interface ip53001.
host1(config)#ip route 10.10.10.0 255.255.255.252 ip ip53001
Prevent DHCP relay from installing host routes this avoids a conflict that can
cause undesirable ARP behavior.
host1(config)#set dhcp relay inhibit-access-route-creation
Chapter 20: Configuring DHCP Relay
Configuring DHCP Relay and BOOTP Relay
501