Contents

Introduction

Prerequisites

Requirements

Components Used

Background

Configure

Configuration on the ASR1006 that acts as a Server

Capturing PPPoE packet on ASR1006

Related Information

Related Cisco Support Community Discussions

Introduction

This document describes how to capture Point-to-Point Packet over Ethernet (PPPoE) packet on an ingress interface of ASR1000 box.

Prerequisites

Requirements

Cisco recommends that you meet these requirements before you attempt this configuration:

- Layer 1 connectivity between ASR1k and the client router is up

Components Used

This document is  restricted to XE version 3.13 and above.

PPPoE Server - ASR1006

PPPoE Client - Any Cisco Router

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Background

This document help a techinician to determine if PPPoE packets are actually hitting the interface of the ASR1k router acting as a PPPoE Server. This is usefull in scenarios where we troubleshoot PPPoE failures.

Configure

Note: Use the Command Lookup Tool (registered customers only) in order to obtain more information on the commands used in this section.

Configuration on the ASR1006 that acts as a Server

A sample of the configuration on ASR1006 that acts as a server is shown here:

interface GigabitEthernet0/0/2 >>>> Interface connecting towards the PPPoE Client

no ip address

negotiation auto

pppoe enable group global

cdp enable

bba-group pppoe global

virtual-template 1

interface Virtual-Template1

ip unnumbered Loopback0

peer default ip address pool test

ppp authentication chap

end

interface Loopback0

ip address 10.1.1.1 255.255.255.255

end

Capturing PPPoE packet on ASR1006

Enable below commands on exec prompt of the ASR1006 router:

ASR# debug platform condition interface GigabitEthernet0/0/2 ingress

ASR# debug platform packet-trace packet 256 fia-trace

ASR# debug platform condition start

ASR# debug platform packet-trace enable

Initiate PPPoE session from the PPPoE Client

ASR# show platform packet-trace summary

ASR# show platform packet-trace summary

Pkt   Input            Output           State  Reason

0     Gi0/0/2          internal0/0/rp:0  PUNT   3   (Layer2 control and legacy)

1     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

2     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

3     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

4     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

5     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

6     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

7     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

8     Gi0/0/2          internal0/0/rp:0  PUNT   27  (Subscriber session control)

Now we can check a specific packet above using:

ASR# show platform packet-trace packet 8

Packet: 8           CBUG ID: 8

Summary

Input     : GigabitEthernet0/0/2

Output    : internal0/0/rp:0

State     : PUNT 27  (Subscriber session control

Timestamp

Start   : 1732092767453258 ns (11/25/2015 09:27:01.520615 UTC)

Stop    : 1732092767494466 ns (11/25/2015 09:27:01.520656 UTC)

Path Trace

Feature: FIA_TRACE

Entry      : 0x802655e0 - PPPOE_GET_SESSION

Lapsed time: 2493 ns

Feature: FIA_TRACE

Entry      : 0x805ce9e4 - ESS_ENTER_SWITCHING

Lapsed time: 1293 ns

The above packet shows that PPPoE packets are hitting the interface.

You can disable the packet tracer as below:

ASR# no debug platform condition interface GigabitEthernet0/0/2 ingress

ASR# no debug platform packet-trace packet 256 fia-trace

ASR# debug platform condition stop

ASR# no debug platform packet-trace enable

Related Information

Embedded Packet Capture