Cisco 827 DSL Router PPPoE Troubleshooting Guide

About this manual

This document serves as a troubleshooting guide for Cisco DSL routers acting as PPPoE clients. It aims to identify and resolve issues preventing a Digital Subscriber Line (DSL) connection from functioning correctly. The guide categorizes potential faults into three layers: Layer 1 (physical connection to the DSLAM), Layer 2 (ATM connectivity and PPPoE/PPPoA protocols), and Layer 3 (IP). This manual is written in Chinese.

What's inside

• Introduction
• Prerequisites
• Layer 1 Troubleshooting
• Layer 2 Troubleshooting
• PPPoE Session Status
• PPP Negotiation
• MTU Adjustment
• Command Usage

Frequently asked questions

What command checks if the ATM interface is administratively down?

Issue the command 'show interface atm 0' in enable mode to check the status.

How do I enable the ATM0 interface if it is administratively down?

Enter the 'no shutdown' command under the ATM0 interface configuration.

Which pins on the RJ-11 connector carry ADSL signals?

Pins 3 and 4 on a 6-pin cable, or pins 2 and 3 on a 4-pin cable, carry the ADSL signals.

What indicates a successful PPPoE session in the 'show vpdn' output?

A successful session shows a non-zero SID and filled RemMAC/LocMAC fields, with the Vast status as UP.