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Troubleshooting Serial Line Problems
frame-relay map command 
missingEnter the show frame-relay map privileged EXEC command to 
see whether an address map is configured for the DLCI.
If you do not see an address map for the DLCI, enter the clear 
frame-relay-inarp privileged EXEC command. Then enter the 
show frame-relay map command again to see if there is now a 
map to DLCI.
If there is no map to the DLCI,...

 
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Cannot Ping End to End
Attempts to ping devices on a remote network across a Frame Relay connection 
fail. Ta b l e 9 - 2 6 outlines causes of this problem and describes possible solutions.
X.25 Problems
This section describes how to troubleshoot the following X.25 symptoms:
No Connections over X.25 Link
Excess Serial Errors on X.25 Link
Table 9-26 Cannot Ping End to End...

 
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No Connections over X.25 Link
Connections over an X.25 link fail.
Ta b l e 9 - 2 7 outlines causes of this problem and describes possible solutions.
Table 9-27 No Connections over X.25 Link
Problem Solution
Incorrect cabling or bad 
router hardware
Check all cabling and hardware for damage or wear. Replace cabling 
or hardware as required. For more information on the Cisco...

 
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Misconfigured protocol 
parametersEnable the debug lapb privileged EXEC command and look for set 
asynchronous balance mode requests (SABMs) being sent. If no 
SABMs are being sent, disable the debug lapb command and enable 
the debug x25 events privileged EXEC command.
Look for RESTART messages (for PVCs) or CLEAR REQUESTS with 
non-zero cause codes (for SVCs).
To...

 
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Excess Serial Errors on X.25 Link
The output of the show interfaces serial 0 privileged EXEC command shows 
rejects (REJs), receiver not ready events (RNRs), protocol frame errors (FRMRs), 
restarts (RESTARTs), or disconnects (DISCs) in excess of 0.5 percent of 
information frames (IFRAMEs).
NoteIf any of these fields is increasing and represents more than 0.5 percent of the...

 
Chapter 9      Troubleshooting
Software Upgrade Methods
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Software Upgrade Methods
Following are the methods for upgrading software on Cisco 800 series and 
Cisco SOHO series routers:
Copy the new software image to Flash memory over the LAN or WAN while 
the existing Cisco IOS software image is operating.
Copy the new software image to Flash memory over the LAN while the boot 
image (ROM monitor) is operating.
Copy the new software image...

 
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Recovering a Lost Password
Changing the Configuration Register
Follow these steps to change a configuration register.
Step 1Connect an ASCII terminal or a PC running a terminal emulation program to the 
CONSOLE port on the rear panel of the router. Refer to the “Connecting the 
Router to a PC” section in the “Installation” chapter of the Cisco 827 Routers 
Hardware Installation Guide.
Step 2Configure the...

 
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Recovering a Lost Password
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Step 5Record the break setting:
Break enabled—bit 8 is set to 0.
Break disabled (default setting)—bit 8 is set to 1.
NoteTo enable break, enter the config-register 0x01 command while in privileged 
EXEC mode.
Resetting the Router
Follow these steps to reset the router.
Step 1If break is enabled, go to Step 2. If break is disabled, turn the router off ( O ), wait 
5 seconds, and turn...

 
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Step 5Enter no in response to the prompts until the following message is displayed:
Press RETURN to get started! 
Step 6Press Return. The following prompt appears:
Router>
Step 7Enter the enable command to enter enable mode. Configuration changes can be 
made only in enable mode: 
Router> enable
The prompt changes to the privileged EXEC prompt:
Router# 
Step 8Enter the show...

 
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Resetting the Password and Saving Your Changes
Follow these steps to reset your password and save the changes.
Step 1Enter the configure terminal command to enter configuration mode:
Router# configure terminal
Step 2Enter the enable secret command to reset the enable secret password in the 
router:
Router(config)# enable secret password
Step 3Enter exit to exit configuration mode:...