Configuring Pppoe Ia Vendor-Tag Stripping On An Interface - Cisco Catalyst 4500 Series Software Configuration Manual

Chapter 51 Configuring the PPPoE Intermediate Agent

Configuring PPPoE IA Vendor-tag Stripping on an Interface

This functionality enables an administrator to strip the vendor-specific tag (VSA) from PADO, PADS,
and PADT packets received on an interface before forwarding them to the user.
The following example shows how to enable stripping on FastEthernet 3/2:
Switch> enable
Switch# configure terminal
Switch(config) interface FastEthernet 3/2
Switch(config-if) pppoe intermediate-agent vendor-tag strip
This setting is disabled by default.
Generally, you would configure vendor-tag stripping on an interfaces connected to the PPPoE server. If
Note
you configure stripping, incoming packets are stripped of their VSAs (which carry subscriber and line
identification information). For this to happen, the PPPoE Intermediate agent must be enabled to make
the pppoe intermediate-agent vendor-tag strip command effective, and the interface must be set to
trust. In isolation, the command has no effect.
Configuring PPPoE IA Circuit-ID and Remote-ID on an Interface
The [no] pppoe intermediate-agent format-type circuit-id command sets the circuit ID on an interface
and overrides the automatic generation of circuit ID by the switch. Without this command, one default
tag (for example, Ethernet x/y:z on the PPPoE to which the user is connected) inserted by an
intermediate-agent.
The [no] pppoe intermediate-agent format-type remote-id command sets the remote ID on an
interface.
This functionality causes tagging of PADI, PADR, and PADT packets (belonging to PPPoE Discovery
stage) received on this physical interface with circuit ID or remote ID. This happens regardless s of their
VLAN if PPPoE IA is not enabled for that VLAN.
You should use remote ID instead of circuit ID for subscriber line identification. You should configure
this setting on every interface where you enabled PPPoE IA because it is not set by default. The default
value for remote-id is the switch MAC address (for all physical interfaces).
The following example shows how to configure the circuit ID as root and the remote ID as granite:
Switch> enable
Switch# configure terminal
Switch(config) interface FastEthernet 3/1
Switch(config-if) pppoe intermediate-agent format-type circuit-id string root
Switch(config-if) pppoe intermediate-agent format-type remote-id string granite
Enabling PPPoE IA for a Specific VLAN on an Interface
This functionality allows you to enable PPPoE IA on either a specific VLAN, a comma-separated list
such as "x,y," or a range such as "x-y."
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
RFCs
51-5