Troubleshooting guide
Make sure you have debug ATM events running on the Cisco DSL Router, and then go to a working
Internet connection and begin to ping the IP address your ISP statically assigned to you.
It does not matter whether you have configured this IP address on the Cisco DSL Router. What is
important is that your ATM interface is up/up and that you are pinging the IP address your ISP gave
you. If you don't see the expected output after the ping test, contact your ISP for support.
4.
Disable debugging on the router.
<< wait 60 seconds >>
Router#undebug all
!−−− Used to turn off the debug events.
All possible debugging has been turned off.
Verify your VPI/VCI values, and then make the necessary changes to your configuration.
If you do not see output during the 60 seconds of debugging, contact your ISP.
5.
Can you ping the default gateway?
In a bridged environment, pinging the default gateway is a good test of connectivity. In general, if you can
ping to your default gateway, you know that Layer 1 and Layer 2 services are functioning properly. Issue the
ping command:
Router#ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round−trip min/avg/max = 44/44/48 ms
Router#
OR
Router#ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100−byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round−trip min/avg/max = 44/44/48 ms
Router#
A successful ping will take one of two forms. The first form will show an 80 percent success rate. The first
ping packet that is sent is lost (.!!!!). This is a successful ping—the first packet is lost while a Layer 2 to Layer
3 binding is created via address resolution protocol (ARP). The second form of the ping is a 100 percent
success rate, which is indicated by five exclamation points.
If your success rate is 80−100 percent, try to ping a valid Internet address (198.133.219.25 is
www.cisco.com). If you can ping the default gateway from the router but you cannot ping another Internet
address, make sure you have only one static default route in the configuration (for example, IP route 0.0.0.0
0.0.0.0 192.168.1.1).
For the example above, if you already have a correct static default route and cannot ping Internet addresses,
contact your ISP to resolve the routing issue.
Cisco DSL Router Configuration and Troubleshooting Guide