Cisco Systems Router 1800 Series User Manual

							
 
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Line Configuration
Perform these steps to configure the line on the V.92 modem, beginning in global configuration mode: 
 Command Purpose
Step 1line line-number  
Example:
Router(config)#  line 1
Router(config-line)
Identifies a specific line for configuration and 
enters line configuration collection mode.
NoteThe number entered here must be the same 
as the number entered for the 
asynchronous serial interface.
Step 2modem inout
Example:
Router(config-line)#  modem inoutRouter(config-line)#
Configures the line for both incoming and 
outgoing calls.
Step 3autoselect {arap  | ppp  | slip  | during-login  | 
timeout  seconds }
Example:
Router(config-line)#  autoselect ppp
Router(config-line)#
Configures the line to automatically start an 
AppleTalk Remote Access (ARA), PPP, or SLIP 
session. 
NoteWe recommend ppp for use with the dial 
backup feature.
Step 4transport input  {all  | lat  | mop  | nasi  | none  | 
pad
 |  rlogin  | telnet  | v120 } 
Example:
Router(config-line)#  transport input allRouter(config-line)#
Defines which protocols can be used to connect to 
the line. 
NoteWe recommend all for use with the dial 
backup feature.
Step 5exit
Example:
Router(config-line)#  exit
Router(config)#
Exits line configuration mode, and enters global 
configuration mode.
  
						

							 
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  Configuring Dial Backup and Remote Management Through a V.92 Modem 
						

							CH A P T E R
 
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14
Troubleshooting
Use the information in this chapter to help isolate problems you might encounter or to rule out the router 
as the source of a problem. This chapter contains the following sections:
 Getting Started
 Before Contacting Cisco or Your Reseller
 ADSL Troubleshooting
 SHDSL Troubleshooting
 ATM Troubleshooting Commands
 Software Upgrade Methods
 Recovering a Lost Password
 Managing Your Router with SDM
Getting Started
Before troubleshooting a software problem, you must connect a terminal or PC to the router using the 
light-blue console port. (For information on making this connection, see the documentation listed in the 
“Related Documents” section on page 14.) With a connected terminal or PC, you can view status 
messages from the router and enter commands to troubleshoot a problem.
You can also remotely access the interface (Ethernet, ADSL, or telephone) by using Telnet. The Telnet 
option assumes that the interface is up and running.
Before Contacting Cisco or Your Reseller
If you cannot locate the source of a problem, contact your local reseller for advice. Before you call, you 
should have the following information ready:
 Chassis type and serial number
 Maintenance agreement or warranty information
 Type of software and version number 
 Date you received the hardware
 Brief description of the problem
 Brief description of the steps you have taken to isolate the problem 
						

							 
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Chapter 14      Troubleshooting
  ADSL Troubleshooting
ADSL Troubleshooting
If you experience trouble with the ADSL connection, verify the following:
 The ADSL line is connected and is using pins 3 and 4. For more information on the ADSL 
connection, see the hardware guide for your router.
 The ADSL CD LED is on. If it is not on, the router may not be connected to the DSL access 
multiplexer (DSLAM). For more information on the ADSL LEDs, see the hardware installation 
guide specific for your router.
 The correct Asynchronous Transfer Mode (ATM) virtual path indentifier/virtual circuit identifier 
(VPI/VCI) is being used.
 The DSLAM supports discrete multi-tone (DMT) Issue 2.
 The ADSL cable that you connect to the Cisco router must be 10BASE-T Category 5, unshielded 
twisted-pair (UTP) cable. Using regular telephone cable can introduce line errors.
SHDSL Troubleshooting
Symmetrical high-data-rate digital subscriber line (SHDSL) is available on the Cisco 1803 router model. 
If you experience trouble with the SHDSL connection, verify the following:
 The SHDSL line is connected and using pins 3 and 4. For more information on the G.SHDSL 
connection, see the hardware guide for your router.
 The G.SHDSL LED is on. If it is not on, the router may not be connected to the DSL access 
multiplexer (DSLAM). For more information on the G.SHDSL LED, see the hardware installation 
guide specific for your router.
 The correct asynchronous transfer mode (ATM) virtual path indentifier/virtual circuit identifier 
(VPI/VCI) is being used.
 The DSLAM supports the G.SHDSL signaling protocol.
Use the show controllers dsl 0 command in privileged EXEC mode to view an SHDSL configuration.
ATM Troubleshooting Commands
Use the following commands to troubleshoot your ATM interface.
 ping atm interface Command
 show interface Command
 show atm interface Command
 debug atm Commands 
						

							 
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Chapter 14      Troubleshooting
  ATM Troubleshooting Commands
ping atm interface Command
Use the ping atm interface command to determine whether a particular PVC is in use. The PVC does 
not need to be configured on the router to use this command. 
Example 14-1 shows the use of this 
command to determine whether PVC 8/35 is in use.
Example 14-1 Determining If a PVC Is in Use
Router# ping atm interface atm 0 8 35 seg-loopback 
Type escape sequence to abort.
Sending 5, 53-byte segment OAM echoes, timeout is 2 seconds:
!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 148/148/148 ms
!----This command sends five OAM F5 loopback packets to the DSLAM (segment OAM packets). 
If the PVC is configured at the DSLAM, the ping is successful.
!----To test whether the PVC is being used at the aggregator, enter the following command:
Router# ping atm interface atm 0 8 35 end-loopback 
Type escape sequence to abort.
Sending 5, 53-byte end-to-end OAM echoes, timeout is 2 seconds:
!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 400/401/404 ms
!----This command sends end-to-end OAM F5 packets, which are echoed back by the 
aggregator.
show interface Command
Use the show interface command to display the status of all physical ports (Ethernet and ATM) and 
logical interfaces on the router. 
Example 14-2 shows sample command output.
Example 14-2 Viewing the Status of Selected Interfaces
Router# show interface atm 0ATM0 is up, line protocol is up 
  Hardware is PQUICC_SAR (with Alcatel ADSL Module)
  Internet address is 14.0.0.16/8  MTU 1500 bytes, sub MTU 1500, BW 640 Kbit, DLY 80 usec, 
     reliability 40/255, txload 1/255, rxload 1/255
  Encapsulation ATM, loopback not set  Keepalive not supported 
  Encapsulation(s):AAL5, PVC mode
  10 maximum active VCs, 1 current VCCs  VC idle disconnect time:300 seconds
  Last input 01:16:31, output 01:16:31, output hang never
  Last clearing of show interface counters never  Input queue:0/75/0 (size/max/drops); Total output drops:0
  Queueing strategy:Per VC Queueing
  5 minute input rate 0 bits/sec, 0 packets/sec  5 minute output rate 0 bits/sec, 0 packets/sec
     512 packets input, 59780 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles     0 input errors, 1024 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 
						

							 
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     426 packets output, 46282 bytes, 0 underruns     0 output errors, 0 collisions, 2 interface resets
     0 output buffer failures, 0 output buffers swapped out
Router# show interface fastethernet 0
Ethernet0 is up, line protocol is up 
Hardware is PQUICC Ethernet, address is 0000.Oc13.a4db (bia0010.9181.1281)
Internet address is 170.1.4.101/24
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255., txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Router# show interface dialer 1
Dialer 1 is up, line protocol is up Hardware is Dialer interface
Internet address is 1.1.1.1/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100000 usec, reliability255/255. txload 1/255, rxload 1/255
Encapsulation PPP, loopback not set
Keepalive set (10 sec)DTR is pulsed for 5 seconds on reset
LCP Closed
Ta b l e 14-1 describes possible command output for the show interface command.
Ta b l e 14-1 show interface Command Output Description 
Output Cause
For ATM Interfaces
ATM 0 is up, line protocol is upThe ATM line is up and operating correctly.
ATM 0 is down, line protocol is down The ATM interface has been disabled with the 
shutdown command
or 
 The ATM line is down, possibly because the 
ADSL cable is disconnected or because the 
wrong type of cable is connected to the ATM 
port.
AT M  0 .n is up, line protocol is up The specified ATM subinterface is up and operating 
correctly.
AT M  0 .n is administratively down, line protocol 
is downThe specified ATM subinterface has been disabled 
with the shutdown command.
AT M  0 .n is down, line protocol is downThe specified ATM subinterface is down, possibly 
because the ATM line has been disconnected (by the 
service provider).
For Fast Ethernet Interfaces
Fast Ethernet n is up, line protocol is upThe specified Fast Ethernet interface is connected to 
the network and operating correctly.
Fast Ethernet n is up, line protocol is downThe specified Fast Ethernet interface has been 
correctly configured and enabled, but the Ethernet 
cable might be disconnected from the LAN. 
						

							 
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Chapter 14      Troubleshooting
  ATM Troubleshooting Commands
show atm interface Command
To display ATM-specific information about an ATM interface, use the show atm interface atm 0 
command from privileged EXEC mode, as shown in 
Example 14-3.
Example 14-3 Viewing Information About an ATM Interface
Router# show atm interface atm 0Interface ATM0:
AAL enabled:  AAL5   AAL2, Maximum VCs: 23, Current VCCs: 0
VCIs per VPI: 1024, 
Max. Datagram Size: 4528
PLIM Type: ADSL - 4608Kbps Upstream, DMT, TX clocking: LINE0 input, 0 output, 0 IN fast, 0 OUT fast
 Avail bw = 4608 
Config. is ACTIVE
Ta b l e 14-2 describes some of the fields shown in the command output.
Fast Ethernet n is administratively down, line 
protocol is downThe specified Fast Ethernet interface has been 
disabled with the shutdown command, and the 
interface is disconnected.
For Dialer Interfaces
Dialer n is up, line protocol is upThe specified dialer interface is up and operating 
correctly.
Dialer n is down, line protocol is down This is a standard message and may not indicate 
anything is actually wrong with the 
configuration
or
 If you are having problems with the specified 
dialer interface, this can mean it is not 
operating, possibly because the interface has 
been brought down with the shutdown 
command, or the ADSL cable is disconnected.
Table 14-1 show interface Command Output Description (continued)
Output Cause
Ta b l e 14-2 show atm interface Command Output Description 
FieldDescription
AT M  i n t e r f a c eInterface number. Always 0 for the Cisco 1800 fixed-configuration routers.
AAL enabledType of AAL enabled. The Cisco 1800 fixed-configuration routers support AAL5.
Maximum VCsMaximum number of virtual connections this interface supports.
Current VCCsNumber of active virtual channel connections (VCCs).
Maximum 
Transmit
 
Channels
Maximum number of transmit channels. 
						

							 
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debug atm Commands
Use the debug commands to troubleshoot configuration problems that you might be having on your 
network. The debug commands provide extensive, informative displays to help you interpret any 
possible problems. 
Guidelines for Using Debug Commands
Read the following guidelines before using debug commands to ensure appropriate results.
 All debug commands are entered in privileged EXEC mode.
 To view debugging messages on a console, enter the logging console debug command.
 Most debug commands take no arguments.
 To disable debugging, enter the undebug all command.
 To  u s e  debug commands during a Telnet session on your router, enter the terminal monitor 
command.
CautionDebugging is assigned a high priority in your router CPU process, and it can render your router unusable. 
For this reason, use debug commands only to troubleshoot specific problems. The best time to use debug 
commands is during periods of low network traffic so that other activity on the network is not adversely 
affected.
You can find additional information and documentation about the debug commands in the Cisco IOS 
Debug Command Reference.
debug atm errors Command
Use the debug atm errors command to display ATM errors. The no form of this command disables 
debugging output. 
Example 14-4 shows a sample output.
Example 14-4 Viewing ATM Errors
Router# debug atm errorsATM errors debugging is on
Router#
01:32:02:ATM(ATM0.2):VC(3) Bad SAP received 450001:32:04:ATM(ATM0.2):VC(3) Bad SAP received 4500
01:32:06:ATM(ATM0.2):VC(3) Bad SAP received 4500
01:32:08:ATM(ATM0.2):VC(3) Bad SAP received 450001:32:10:ATM(ATM0.2):VC(3) Bad SAP received 4500
Max Datagram 
SizeConfigured maximum number of bytes in the largest datagram.
PLIM TypePhysical layer interface module (PLIM) type.
Table 14-2 show atm interface Command Output Description (continued)
Field Description 
						

							 
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debug atm events Command
Use the debug atm events command to display events that occur on the ATM interface processor and to 
diagnose problems in an ATM network. This command provides an overall picture of the stability of the 
network. The no form of this command disables debugging output.
If the interface is successfully communicating with the Digital Subscriber Line Access Multiplexer 
(DSLAM) at the telephone company, the modem state is 0x10. If the interface is not communicating with 
the DSLAM, the modem state is 0x8. 
Example 14-5 shows an ADSL line that is up and communicating 
successfully. Example 14-6 shows an ADSL line that is not communicating correctly. Note that the 
modem state does not transition to 0x10.
Example 14-5 Viewing ATM Interface Processor Events—Success
Router# debug atm events
Router#
00:02:57: DSL: Send ADSL_OPEN command.00:02:57: DSL: Using subfunction 0xA
00:02:57: DSL: Using subfunction 0xA
00:02:57: DSL: Sent command 0x500:02:57: DSL: Received response: 0x26
00:02:57: DSL: Unexpected response 0x26
00:02:57: DSL: Send ADSL_OPEN command.
00:02:57: DSL: Using subfunction 0xA00:02:57: DSL: Using subfunction 0xA
00:02:57: DSL: Sent command 0x5
00:03:00: DSL: 1: Modem state = 0x800:03:02: DSL: 2: Modem state = 0x10
00:03:05: DSL: 3: Modem state = 0x10
00:03:07: DSL: 4: Modem state = 0x1000:03:09: DSL: Received response: 0x24
00:03:09: DSL: Showtime!
00:03:09: DSL: Sent command 0x1100:03:09: DSL: Received response: 0x61
00:03:09: DSL: Read firmware revision 0x1A04
00:03:09: DSL: Sent command 0x3100:03:09: DSL: Received response: 0x12
00:03:09: DSL: operation mode 0x0001
00:03:09: DSL: SM: [DMTDSL_DO_OPEN -> DMTDSL_SHOWTIME]
Example 14-6 Viewing ATM Interface Processor Events—Failure
Router# debug atm events
Router#00:02:57: DSL: Send ADSL_OPEN command.
00:02:57: DSL: Using subfunction 0xA
00:02:57: DSL: Using subfunction 0xA00:02:57: DSL: Sent command 0x5
00:02:57: DSL: Received response: 0x26
00:02:57: DSL: Unexpected response 0x2600:02:57: DSL: Send ADSL_OPEN command.
00:02:57: DSL: Using subfunction 0xA
00:02:57: DSL: Using subfunction 0xA00:02:57: DSL: Sent command 0x5
00:03:00: DSL: 1: Modem state = 0x8
00:03:00: DSL: 1: Modem state = 0x800:03:00: DSL: 1: Modem state = 0x8
00:03:00: DSL: 1: Modem state = 0x8
00:03:00: DSL: 1: Modem state = 0x800:03:00: DSL: 1: Modem state = 0x8 
						

							 
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debug atm packet Command
Use the debug atm packet command to display all process-level ATM packets for both outbound and 
inbound packets. The output reports information online when a packet is received or a transmission is 
attempted. The no form of this command disables debugging output.
CautionBecause the debug atm packet command generates a significant amount of output for every packet 
processed, use it only when network traffic is low, so that other system activities are not adversely 
affected.
The command syntax is:
debug atm packet [interface atm number [vcd vcd-number] [vc vpi/vci number]]
no debug atm packet [interface atm number [vcd vcd-number] [vc vpi/vci number]]
where the keywords are defined as follows:
interface atm number(Optional) ATM interface or subinterface number.
vcd vcd-number(Optional) Number of the virtual circuit designator (VCD).
vc vpi/vci number VPI/VCI value of the ATM PVC.
Example 14-7 shows a sample output.
Example 14-7 Viewing ATM Packet Processing
Router# debug atm packet
Router#01:23:48:ATM0(O):
VCD:0x1 VPI:0x1 VCI:0x64 DM:0x0 SAP:AAAA CTL:03 OUI:000000 TYPE:0800 Length:0x70
01:23:48:4500 0064 0008 0000 FF01 9F80 0E00 0010 0E00 0001 0800 A103 0AF3 17F7 0000 01:23:48:0000 004C BA10 ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD 
01:23:48:ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD 
01:23:48:ABCD ABCD ABCD ABCD ABCD 01:23:48:
01:23:48:ATM0(I):
VCD:0x1 VPI:0x1 VCI:0x64 Type:0x0 SAP:AAAA CTL:03 OUI:000000 TYPE:0800 Length:0x7001:23:48:4500 0064 0008 0000 FE01 A080 0E00 0001 0E00 0010 0000 A903 0AF3 17F7 0000 
01:23:48:0000 004C BA10 ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD 
01:23:48:ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD ABCD 01:23:48:ABCD ABCD ABCD ABCD ABCD 
01:23:48:
Ta b l e 14-3 describes some of the fields shown in the debug atm packet command output.
Ta b l e 14-3 debug atm packet Command Output Description 
Field Description
AT M 0Interface that is generating the packet.
(O)Output packet. (I) would mean receive packet.
VCD: 0xnVirtual circuit associated with this packet, where n is some value.
VPI: 0xnVirtual path identifier for this packet, where n is some value.