Cisco 1751 - Manual (Page 56)

Chapter 3 Troubleshooting
Problem Solving
3-14
Cisco 1751 Router Hardware Installation Guide
78-11258-04
Fan Behavior
Under normal operation, the fan on the Cisco 1751 router is off. The fan turns on
automatically, as required, to cool the system.
ISDN S/T
or
ISDN U Card cannot
make a
connection to
the remote
router. Use show isdn status
command to check the
following:
Does the current ISDN
switch type match actual
switch type being used? Use the isdn switch-type command
to configure correct switch type.
Is Layer 1 status
deactivated? Use the show controller bri0
command to check for the messages
CO RUNNING LOOPBACK TESTS
or CO TESTING. If you receive these
messages, contact the service
provider.
If Layer 1 status is active,
does Layer 3 status say “2
Active Layer 3 calls”? Router might have called itself.
Check destination phone number
configured with the dialer map
command or the dialer string
command.
If Layer 1 status is active,
does Layer 3 status say
“No Active Layer 3
call(s)”? Check destination phone number and
make sure it matches the remote
router phone number. Check route to
the destination and make sure it
matches the remote router network
address.
If Layer 1 status is active,
does Layer 3 status say “1
Active Layer 3 call”? Check router protocol
configurations.
Table 3-4 Troubleshooting ISDN (continued)
WIC Symptom Check the Following Possible Solution(s)