Troubleshooting guide

!−−− Confirm your PVC values with your ISP.
!
bridge−group 1
!
bridge 1 protocol ieee
!
end
Troubleshoot Your Configuration
If your ADSL service is not working properly, see Troubleshooting a PC PPPoE Client.
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Cisco DSL Router Configuration and Troubleshooting
Guide
RFC1483 Bridging with IRB – Troubleshooting
Determine the Layer to Troubleshoot
There are many reasons why your Digital Subscriber Line (DSL) connection may not be functioning properly.
The goal of this section is to isolate the cause of the failure and repair it. The first troubleshooting step is to
determine which layer of your Asynchronous Digital Subscriber Line (ADSL) service is failing. There are
three layers in which the failure can occur.
Layer 1 – DSL physical connectivity to your ISP's Digital Subscriber Line Access Multiplexer
(DSLAM)
•
Layer 2.1 – ATM connectivity•
Layer 2.2 – Point−to−Point Protocol over ATM (PPPoA), Point−to−Point Protocol over Ethernet
(PPPoE), RFC1483 Bridging, or RFC1483 Routing
•
Layer 3 – IP•
The easiest way to determine which layer you should begin troubleshooting is to issue the command show ip
interface brief. The output of this command differs slightly depending on your configuration.
827−ESC#show ip interface brief
Interface IP−Address OK? Method Status Protocol
ATM0 unassigned YES manual up up
ATM0.1 unassigned YES unset up up
Ethernet0 10.10.10.1 YES manual up up
If the statuses of ATM0 and ATM0.1 are up and the protocol is up, begin troubleshooting at Layer 2.
If the ATM interfaces are down, or if they keep coming up and then going down (they don't stay up and up),
begin troubleshooting at Layer 1.
Cisco DSL Router Configuration and Troubleshooting Guide