This guide provides troubleshooting steps for configuring and resolving Layer 1 and Layer 2 issues on Cisco 827 DSL routers using RFC1483 bridging.
This document is a troubleshooting guide for Cisco 827 DSL routers specifically addressing issues related to RFC1483 bridging. It helps users identify and resolve configuration and fault problems occurring at the first and second layers of the network stack.
The guide is structured into two main sections: Layer 1 problems and Layer 2 problems. For Layer 1, it covers physical connectivity checks, including carrier detection (CD) light status, DSLAM compatibility, physical port connections, pinout verification, power supply requirements, and DSL operating mode configuration. For Layer 2, it details steps to verify PVC values (VPI/VCI), test connectivity to the default gateway, check bridge port forwarding states, and inspect bridge table entries. This manual is written in Chinese.
Enter the command 'show interface atm 0' in enable mode. If the output shows 'ATM0 is administratively down, line protocol is down', the interface is administratively down.
Use the command 'show spanning-tree'. If the output indicates 'Port 3 (ATM0) of Bridge group 1 is forwarding', the port is in the forwarding state.