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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, add a static address map by 
entering the frame-relay map command in serial interface 
configuration mode.
1 For complete information on configuring 
Frame Relay address maps, refer to the Cisco IOS Wid e- Are a 
Networking Configuration Guide publication.
Make sure that the DLCIs and next-hop addresses specified in 
frame-relay map commands are correct. The specified protocol 
address should be in the same network as your local Frame Relay 
interface. 
No broadcast keyword in 
frame-relay map statements
Enter the show running-config privileged EXEC command on 
the local and remote routers to view the router configuration. 
Check frame-relay map command entries to see if the broadcast 
keyword is specified.
If the keyword is not specified, add the broadcast keyword to all 
frame-relay map commands. By default, the broadcast keyword 
is added to dynamic maps learned via Inverse ARP.
1. You can eliminate the need for static Frame Relay address maps by using Inverse Address Resolution Protocol (ARP) instead. 
Use the frame-relay interface-dlci dlci broadcast interface configuration command to configure an interface to use Inverse 
ARP. For more information about the use of this command, refer to the Cisco IOS Wide-Area Networking Configuration 
Guide and Wide-Area Networking Command Reference.
Table 9-25 Cannot Ping Remote Router (continued)
Problem Solution 
						

							 
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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
Problem Solution
Split horizon problem In a partially meshed Frame Relay environment, you must configure 
subinterfaces to avoid problems with split horizon. For detailed 
information on configuring subinterfaces, refer to the Wide-Area 
Networking Configuration Guide and Wide-Area Networking 
Command Reference.
No default gateway on 
workstation
From a local workstation or server, try to ping the remote 
workstation or server. Make several attempts to ping the remote 
device if the first ping is unsuccessful.
If all your attempts fail, check to see whether the local workstation 
or server can ping the Frame Relay interface of the local router.
If you are unable to ping the Frame Relay interface of the local 
router, check the local workstation or server to see whether it is 
configured with a default gateway specification.
If there is no default gateway specified, configure the device with 
a default gateway. The default gateway should be the address of 
the LAN interface of the local router. For information on viewing 
or changing the default gateway of the workstation or server, refer 
to the vendor documentation. 
						

							 
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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 805 
router and serial cables, refer to the Cisco 805 Router Hardware 
Installation Guide.
Enter the show interfaces serial 0 privileged EXEC command to 
determine the status of the interface. 
If the interface is down, see the “Troubleshooting Serial Line 
Problems” section on page 9-16. If the interface is up but the line 
protocol is down, check the Link Access Procedure, Balanced 
(LAPB) state in the output of the show interfaces serial 0 command.
If the LAPB state is not CONNECT, use the debug lapb privileged 
EXEC command (or attach a serial analyzer) to look for set 
asynchronous balance mode requests (SABMs) being sent, and for 
UA packets being sent in reply to SABMs. If UAs are not being sent, 
one of the other possible problems described in this table is the likely 
cause.
If the show interfaces serial 0 command indicates that the interface 
and line protocol are up but no connections can be made, there is 
probably a router or switch misconfiguration. Refer to the other 
possible problems outlined in this table.
Link is down Enter the show interfaces serial 0 privileged EXEC command to 
determine whether the link is down. If the link is down, see the 
“Troubleshooting Serial Line Problems” section on page 9-16. 
						

							 
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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 interpret X.25 cause and diagnostic codes provided in the debug 
x25 events output, refer to the Debug Command Reference 
document.
Verify that all critical LAPB parameters (modulo, T1, N1, N2, and k) 
and the critical X.25 parameters (modulo, X.121 addresses, SVC 
ranges, PVC definitions, and default window and packet sizes) match 
the parameters required by the X.25 service provider.
Misconfigured x25 map 
command
Use the show running-config privileged EXEC command to view 
the router configuration. Look for x25 map command entries under 
the serial interface.
Make sure that x25 map commands specify the correct address 
mappings.
If dynamic routing is being used in the network, verify that the 
broadcast keyword is included in the x25 map command.
Make sure that all router X.25 configuration options match the 
settings of attached switches. Reconfigure the router or the switch as 
necessary.
Enable the debug x25 events privileged EXEC command and look 
for 
RESTART messages (for PVCs) or CLEAR REQUESTS with non-zero 
cause codes (for SVCs). To interpret X.25 cause and diagnostic codes 
provided in the debug x25 events output, refer to the Debug 
Command Reference document.
Table 9-27 No Connections over X.25 Link (continued)
Problem Solution 
						

							 
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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 
number of IFRAMEs, there is likely a problem somewhere in the X.25 network. 
There should always be at least one SABM. However, if there are more than 10, 
the packet switch probably is not responding.
Ta b l e 9 - 2 8 outlines causes of this problem and describes possible solutions.
Table 9-28 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 805 
router and serial cables, refer to the Cisco 805 Router Hardware 
Installation Guide.
Enter the show interfaces serial 0 privileged EXEC command to 
determine the status of the interface. 
If the interface is down, see the “Troubleshooting Serial Line 
Problems” section on page 9-16. If the interface is up but the line 
protocol is down, check the LAPB state in the output of the show 
interfaces serial 0 command.
If the LAPB state is not CONNECT, use the debug lapb privileged 
EXEC command (or attach a serial analyzer) to look for SABMs 
being sent, and for UA packets being sent in reply to SABMs. If UAs 
are not being sent, one of the other possible problems described in 
this table is the likely cause.
If the show interfaces serial 0 command indicates that the interface 
and line protocol are up but no connections can be made, there is 
probably a router or switch misconfiguration. Refer to the other 
possible problems outlined in this table. 
						

							 
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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 over the console port while in ROM monitor 
mode.
From the ROM monitor mode, boot the router from a software image that is 
loaded on a TFTP server. To use this method, the TFTP server must be on the 
same LAN as the router.
Recovering a Lost Password
This section describes how to recover a lost enable or enable secret password. The 
process of recovering a password consists of the following major steps:
1.Changing the Configuration Register
2.Resetting the Router
3.Resetting the Password and Saving Your Changes (for lost enable secret 
passwords only)
4.Resetting the Configuration Register Value
NoteThese procedures can be done only when you are connected to the router through 
the console port. These procedures cannot be performed through a Telnet session.
NoteSee the “Hot Tips” section on Cisco Connection Online (CCO) for additional 
information on replacing enable secret passwords. 
						

							 
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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 terminal to operate at 9600 baud, 8 data bits, no parity, and 
1stopbit.
Step 3At the privileged EXEC prompt (router_name>), enter the show version 
command to display the existing configuration register value :
820-uut2#sh ver
Cisco Internetwork Operating System Software 
IOS (tm) C827 Software (C827-NSY6-M), Version 12.0
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 22-Nov-99 11:20 by dahsue
Image text-base:0x80013170, data-base:0x8081B748
ROM:System Bootstrap, Version 12.0(19990519:174856) 
[jakumar-twister_dev 1055], DEVELOPMENT SOFTWARE
Jay uptime is 48 minutes
System returned to ROM by reload
Running default software
CISCO C827 (MPC855T) processor (revision 0x00) with 19456K/1024K bytes 
of memory.
Processor board ID 00000000, with hardware revision 0000
CPU rev number 5
Bridging software.
4 POTS Ports
1 Ethernet/IEEE 802.3 interface(s)
1 ATM network interface(s)
128K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read/Write)
Configuration register is 0x100
Step 4Record the setting of the configuration register. It is usually 0x2100 or 0x100.  
						

							 
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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 it on ( | ) again. Within 60 seconds, press the Break key. The 
terminal displays the ROM monitor prompt. Go to Step 3.
NoteSome terminal keyboards have a key labeled Break. If your keyboard does 
not have a Break key, refer to the documentation that came with the 
terminal for instructions on how to send a break. 
Step 2Press Break. The terminal displays the following prompt:
rommon 2>
Step 3Enter confreg 0x142 to reset the configuration register:
rommon 2> confreg 0x142
Step 4Initialize the router by entering the reset command:
rommon 2> reset
The router cycles its power, and the configuration register is set to 0x142. The 
router uses the boot ROM system image, indicated by the system configuration 
dialog:
--- System Configuration Dialog ---  
						

							 
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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 startup-config command to display an enable password in the 
configuration file:
Router# show startup-config
If you are recovering an enable password, skip the following “Resetting the 
Password and Saving Your Changes” section on page 9-59, and complete the 
password recovery process by performing the steps in the “Resetting the 
Configuration Register Value” section on page 9-59.
If you are recovering an enable secret password, it is not displayed in the 
show startup-config command output. Complete the password-recovery process 
by performing the steps in the following “Resetting the Password and Saving 
Yo u r  C h a n g e s” section on page 9-59.  
						

							 
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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:
Router(config)# exit
Step 4Save your configuration changes:
Router# copy running-config startup-config
Resetting the Configuration Register Value
After you have recovered or reconfigured a password, reset the configuration 
register value:
Step 1Enter the configure terminal command to enter configuration mode:
Router# configure terminal
Step 2Enter the configure register command and the original configuration register 
value that you recorded.
Router(config)# config-reg value
Step 3Enter exit to exit configuration mode:
Router(config)# exit