Preventing and Troubleshooting Problems        20

The following topics are discussed:

•   "Preventing Problems from Occurring" on page 20-1

•   "Identifying Network Problems-Simple Steps" on page 20-2

•   "Identifying Network Problems-Additional Approaches" on page 20-6

•   "Solving Network Problems" on page 20-14

See the Command Line Administrator's Guide for more detailed command descriptions and instructions.

Preventing Problems from Occurring

Resetting Ports

Use the following commands to reset all ports or specific ports:

Command> reset all Command> reset S0|W1|P0|V0

Backing Up the PortMaster Configuration

The backup file is not in human-readable form but can be reloaded by means of the pminstall program. The program used to back up the PortMaster configuration is /usr/portmaster/pmreadconf.

Once the output file is created, change its permissions to 600 and move the file to the /usr/portmaster/pm_data directory, where it can be read by pminstall.

Use the following commands to back up your PortMaster configuration:

# /usr/portmaster/pmreadconf pm_name pm_passwd output_file # chmod 600 output_file # mv output_file /usr/portmaster/pm_data

Identifying Network Problems-Simple Steps

•   "1-Determine the Software Version" on page 20-3

•   "2-Enter Diagnostic Mode" on page 20-3

•   "3-Verify Your Network Connections" on page 20-4

•   "4-Verify Your Configuration" on page 20-4

If these steps are ineffective, use the information under "Identifying Network Problems-Additional Approaches" on page 20-6.

If you cannot identify the problem, contact Livingston Technical Support.

Note ¯ Always include the version number of your ComOS when reporting problems to Livingston Technical Support. Refer to "1-Determine the Software Version" on page 20-3 for instructions.

1-Determine the Software Version

Command> version

Note ¯ The command line can be accessed from a console terminal regardless of network condition.

2-Enter Diagnostic Mode

1. Make sure the power switch on the PortMaster is set to OFF.

2. Attach a terminal or workstation to the console port S0-or C0-using a null modem cable.

   Configure the terminal or workstation in terminal emulation mode for 9600 baud, 8 data bits, 1 stop bit, and no parity. For more information, refer to the hardware installation guide that came with your PortMaster.

3. Set DIP switch 1 on the back of the PortMaster to the up position.

   DIP switch 1 is the leftmost switch. Refer to your hardware installation guide for detailed information about the PortMaster DIP switches.

4. Turn the power on and observe the diagnostic output.
   • If the PortMaster completes its diagnostics and produces a login: prompt, the PortMaster booted correctly.

   • If not, you might need to boot the PortMaster from the network. See "Booting from the Network" on page 20-15 for instructions.

Refer to the troubleshooting chapter of your hardware installation guide for more information on diagnostic boot messages.

3-Verify Your Network Connections

If no reply is received, connectivity is failing somewhere on your network between the machine issuing the ping request and the specified device.

To ping a device on your network, use the following command:

Command> ping Ipaddress

To stop the ping process, enter the command with no IP address or hostname.

If you do not receive a response to the ping command, verify the following:

• Verify that the host you pinged is running and connected to the Ethernet.

• Verify that all cables are connected to the PortMaster properly.

• If the machine you pinged is on another subnet, verify that you are using the correct subnet mask.

4-Verify Your Configuration

The ifconfig flags are described in Table 20-1.

Table 20-1 ifconfig Flags

Flag	Description
IP_UP	Indicates that the interface is up and running the IP protocol.
IP_DOWN	Indicates that the IP protocol is not in use.
IPX_UP	Indicates that the interface is up and running the IPX protocol.
IPX_DOWN	Indicates that the IPX protocol is not in use.
BROADCAST	Indicates that this is an Ethernet interface.
POINT_TO_POINT	Indicates that the network connection on this interface is a point-to-point connection.
LISTEN	Indicates that the interface is set to listen for RIP packets but not broadcast them.
RIPSEND	Indicates that RIP packets are being sent out from the interface but are not listened for.
OSPF	Indicates that the OSPF protocol is enabled.
PRIVATE	Indicates that no routing information is being sent or listened to on this interface.
SUSPENDED	Indicates that this interface is set for on-demand dial-out operation and is available, but does not have an active connection to the remote site.
COMPRESS	Van Jacobson TCP/IP header compression is being done on this interface.
STAC	Stac LZS data compression is being done on this interface.

The second and third lines of the ifconfig response contain the information described in Table 20-2.

Table 20-2 Additional ifconfig Information

Information	Description
inet	Indicates the IP address of the interface.
dest	Indicates the destination IP address of a point-to-point connection.
netmask	Indicates the netmask for the IP address shown in inet or dest.
broadcast	Indicates the broadcast address of the interface-on Ethernet interfaces only.
mtu	Indicates the maximum transmission unit (MTU) for the interface.
ipxnet	Indicates the IPX network number of the interface.
ipxframe	Indicates the IPX frame type for the interface-on Ethernet interfaces only.

Identifying Network Problems-Additional Approaches

•   "Establishing an Administrative Telnet Session" on page 20-6

•   "Tracing Routes with IP" on page 20-7

•   "Tracing Packets" on page 20-8

•   "Disabling a Synchronous Hardwired Port" on page 20-9

•   "Verifying Port State for Old and New Cards" on page 20-9

•   "Debugging and Interpreting PPP Negotiation" on page 20-9

Establishing an Administrative Telnet Session

Establishing a Telnet Session. To establish an administrative Telnet session, telnet to your PortMaster and log in as !root with your administrative password.

Displaying Telnet Messages. You can use the set console command to set the port used for an administrative Telnet session as the console port. Doing so allows you to display messages sent to this port on the console terminal or workstation. To release the Telnet port from console use, use the reset console command. Livingston recommends that you reset the console at the end of every Telnet session.

Troubleshooting the Session. If you are having trouble establishing an administrative Telnet session, do the following on the PortMaster:

1. Verify the TCP port used for Telnet access with the show global command.

2. Check for Telnet sessions by using the show netconns command and looking for administrative connections to that port.

3. Reset any unused connections with the reset nHandle command.

Replace Handle with the network number shown in the first column of the show netconns output.

Note ¯ Although you can have up to four Telnet sessions, you can have only one pmcommand, pmconsole, pminstall, or pmreadconf program running at one time with a given PortMaster, unless you use the set maximum pmconsole Number command to increase the default to a number between 1 and 10.

Tracing Routes with IP

To trace the route to a remote host, use the following command:

Command> traceroute Ipaddress

To stop the traceroute utility, issue the command with no IP address.

Tracing Packets

The ptrace command uses the name of a filter as its argument. All packets passing through the PortMaster are evaluated against the selected filter, except for UDP and ICMP packets that are generated by the PortMaster itself.

Packets that are permitted by the filter are displayed on the console with the following packet information:

• Source address of the packet

• Destination address of the packet

• Protocol

• Other protocol-specific information, including source and destination port

You can also display the name of the interface through which the packets are passing, in addition to the packets defined by the filter, by using the following command:

Command> ptrace Filtername extended

If no filter is specified with the ptrace command, packet tracing is disabled.

Caution ¯ When debugging from a Telnet session, be very careful not to use ptrace on Telnet packets going between the PortMaster and the host from which you are using Telnet. Doing so can create an endless loop of messages.

The following example uses a filter named all that denies all Telnet packets while allowing all other IP traffic for evaluation

Command> add filter all Command> set filter all 1 deny tcp src eq 23 Command> set filter all 2 deny tcp dst eq 23 Command> set filter all 3 permit Command> ptrace all

:

To stop viewing packet trace information, use the following command:

Command> ptrace

Disabling a Synchronous Hardwired Port

To disable a synchronous hardwired port, use the following commands:

Command> set W1 protocol PPP Command> set W1 address 0.0.0.0 Command> set W1 destination 0.0.0.0 Command> reset W1

Verifying Port State for Old and New Cards

This behavior is normal. On older expansion cards, the value of carrier detect (CD) floats high in contrast to the carrier value on the main system card. On more recent expansion cards, the carrier detect value is pulled low as it is on the main system card.

On both old and new cards, a port should show a status of IDLE when modems are attached with hardware flow control set and modem control is turned on for the port. For more information about port states, refer to Chapter 2, "How PortMasters Work."

Debugging and Interpreting PPP Negotiation

To debug PPP negotiations, use the following commands:

Command> set console Command> set debug 0x51

To stop the debug output, use the following commands:

Command> set debug off Command> reset console

PPP Quick Reference

All values shown in the fields are in hexadecimal. Adjacent frames can be separated by a single flag. Address and control bytes are omitted in non-LCP frames if Address-and-Control-Field-Compression is negotiated.

If the first byte of the Protocol field is zero, it is omitted in non-LCP frames if Protocol-Field-Compression is negotiated. On asynchronous links, special characters-flags, escape characters, and control characters selected in the negotiated remote Async-Control-Character-Map-between the flags are replaced by an escape character (7D) and the original byte with bit 6 inverted (XOR'ed with 0x20).

  Table 20-3 shows the values that appear in the Protocol field of a PPP frame. The Network Control Protocol (NCP) value is used to establish a connection for the associated data transfer protocol. See RFC 1700, Assigned Numbers, for a complete list.

Table 20-3 Protocol Values

Protocol	Value	NCP Value
Internet Protocol (IP)	0021	8021
OSI Network Layer	0023	8023
DECnet Phase IV	0027	8027
AppleTalk	0029	8029
Novell IPX	002B	802B
Van Jacobson Compressed TCP/IP	002D
Van Jacobson Uncompressed TCP/IP	002F
Banyan VINES	0035	8035
Link Control Protocol (LCP)		C021
Password Authentication Protocol (PAP)		C023
Link Quality Report (LQM)		C025
Challenge Handshake Authentication Protocol (CHAP)		C223

Solving Network Problems

•   "Replacing Forgotten Passwords" on page 20-14

•   "Booting from the Network" on page 20-15

•   "Booting from PROM" on page 20-18

•   "Resetting the Configuration to Factory Defaults" on page 20-22

•   "Erasing and Reloading ComOS" on page 20-23

•   "Erasing ComOS and the Configuration" on page 20-24

•   "Erasing Specific Files from the Configuration" on page 20-25

Replacing Forgotten Passwords

1. Place the PortMaster in diagnostic mode by setting DIP switch 1 in the up position.

2. Log in to the PortMaster at the PortMaster Console login: prompt using !root and a password of override.

   A case-sensitive, 16-character encrypted challenge is displayed.

3. Contact Livingston Technical Support for the appropriate 16-character one-time encrypted response.

   For information about contacting Technical Support, see the preface of this guide.

4. Log in to the PortMaster as !root, and enter the 16-character encrypted response given by technical support as the password.

   Note ¯ Both the challenge and the response are case-sensitive.

5. Change the administrative password using the set password command.

6. Enter the save all command to save the new password to nonvolatile memory.

Booting from the Network

Note ¯ You can boot a PortMaster from the network only if you have a host on the Ethernet that supports the Trivial File Transfer Protocol (TFTP) and Reverse Address Resolution Protocol (RARP), and is on the same Ethernet segment as the PortMaster. Any host capable of TFTP can be used to boot a PortMaster from the network. Otherwise, you must boot from the PROM monitor using the download command. See

Network booting is necessary if the Flash RAM on your PortMaster becomes corrupted. You can assume that the Flash RAM is corrupt if any of the following occur:

• Your PortMaster never reaches the login: prompt during self-diagnostics-when DIP switch 1 is up.

• A checksum error on the ComOS is reported during the diagnostic boot process.

• Three upgrade attempts prove unsuccessful on a PortMaster running ComOS version 3.0.4 or earlier or IRX ComOS version 3.0.1R or earlier. In this case, ComOS has run out of file descriptors.

Network booting is also required if you have forgotten the administrative password on a PortMaster running a ComOS version earlier than 2.4, or an IRX ComOS version earlier than 1.8R.

To boot your PortMaster from the network, follow these steps:

1. Make sure the power switch on the PortMaster is set to OFF.

2. Access the Livingston FTP site, and download the README.NETBOOT file by entering the following commands at your Ethernet TFTP boot host:

   % ftp ftp.livingston.com Name: anonymous Password: your email address ftp> binary ftp> cd pub/livingston ftp> get README.NETBOOT ftp> quit

3. Read the README.NETBOOT file to determine which netbootable ComOS to download using FTP.

   The ComOS is referred to as GENERIC.OS in the rest of this procedure.

4. Repeat Step 1 to download the appropriate GENERIC.OS.

5. Add the Ethernet address of the PortMaster to your /etc/ethers file or your Network Information Service (NIS) map.

6. Start the rarpd service, if it is not already running, by entering the following command:

   % rarpd -a

   Note ¯ The command might vary depending on your operating system. Refer to your system manual for more information about running rarpd.

7. Set up TFTP on your boot host by entering the following commands:

   % umask 22 % mkdir /tftpboot % mv GENERIC.OS /tftpboot/GENERIC.OS % cd /tftpboot % ln -s . tftpboot

   
   Replace GENERIC.OS with one of the following filenames:

   PortMaster Model	Filename
   PM2	GENERIC.PM2
   OR	GENERIC.PMO
   P25	GENERIC.P25
   IRX	GENERIC.IRX
   PM3	GENERIC.PM3

8. Using a text editor, uncomment the tftp command entry in the /etc/inetd.conf file.

   To have the inetd daemon reread the /etc/inetd.conf file, send a SIGHUP signal to the inetd process.

   This procedure applies to most UNIX systems. However, the procedure for enabling TFTP on your system might vary. Consult your system documentation.

9. On the PortMaster, set DIP switch 2 to up and turn the power switch ON.

10. Boot the PortMaster, and log in as !root with no password.

11. To save your PortMaster configuration before reformatting the Flash RAM, enter the following on your UNIX host:

    % /usr/portmaster/pmreadconf pm_name pm_password output_file

    You can also save the configuration with PMconsole. See the PMconsole for Windows Administrator's Guide for more information.

12. Alternatively, if your ComOS is corrupted, erase and reconfigure the Flash RAM on your PortMaster.

    Occasionally, the cause of Flash RAM corruption can be your configuration settings. If this is the case, you must erase and reformat your Flash RAM. See "Resetting the Configuration to Factory Defaults" on page 20-22 for instructions.

    You must reconfigure your PortMaster completely after you have installed the new ComOS in Flash RAM.

13. Set the IP address of the Ethernet port on the PortMaster, if necessary.

    If you have chosen one of the noconfig files to boot, set the IP address of the PortMaster so that you can connect to the PortMaster from a remote host.

    Use the following command:

    Command> ifconfig ether0 address Ipaddress

    In this case, 192.168.200.1 is the IP address of the PortMaster.

14. Enter the netmask, if necessary.

    If you are using a netmask other than 255.255.255.0 on your network, you must enter it now. Use the following command, substituting your netmask:

    Command> ifconfig ether0 netmask Netmask

15. Install the new ComOS into the Flash RAM by using the pminstall utility.

16. After the new ComOS is installed, prepare the PortMaster for operation by doing the following:

    a. Turn off the power on the PortMaster.

    
    b. Remove the terminal from the console port.

    
    c. Return the DIP switches to their normal operating positions.

    
    d. Turn on the power to reboot the PortMaster.

17. If the PortMaster is running properly, reenter your PortMaster configuration settings.

Booting from PROM

Note ¯ This procedure works only with PROMs of level F or higher. The PROM version is displayed at boot time if the console port is in diagnostic mode.

Beginning with PROM level F, you can boot your PortMaster remotely from any host with TFTP capability in one of the following ways using the PROM instead of RARP:

• Boot from the tftpd daemon.

• Send a ComOS version from your workstation to the console port on the PortMaster over a serial cable and boot from that.

  To boot your PortMaster from PROM, follow these steps:

1. Make sure the power switch on the PortMaster is set to OFF.

2. Place the PortMaster in diagnostic mode as described in "2-Enter Diagnostic Mode" on page 20-3.

3. Attach a terminal to the console port of the PortMaster.

4. Turn the power switch to ON.

5. As the PortMaster starts to boot, press the Escape key to display an angle bracket (>) prompt.

   You can also type a caret and a left square bracket (^[) to display the prompt.

6. To prepare the PortMaster for remote booting, enter one or more of the commands shown in Table 20-4 on the PortMaster console.

   Table 20-4 PROM Commands

   Command	Description
   address	Allows you to set the address of the Ethernet interface.
   netmask	Allows you to set the netmask of the Ethernet interface. The default is 255.255.255.0.
   gateway	Allows you to set the default gateway in order to boot from a server on another network.
   tftp	Causes the PortMaster to issue the TFTP request to the boot server.
   download	Allows you to download ComOS using the serial port.
   continue	Causes the PortMaster to continue attempting to boot using RARP.

7. Enter the address of the PortMaster Ethernet port:

   > address Ipaddress

8. Set the netmask and gateway, if needed:

   > network Netmask > gateway Ipaddress

9. Access the Livingston FTP site, and download the README.NETBOOT file by entering the following commands at your Ethernet TFTP boot host:

   % ftp ftp.livingston.com Name: anonymous Password: your email address ftp> binary ftp> cd pub/livingston ftp> get README.NETBOOT ftp> quit

10. Read the README.NETBOOT file to determine which netbootable ComOS to download using FTP.

    The ComOS is referred to as GENERIC.OS in the rest of this procedure.

11. Repeat Step 9 to download the appropriate GENERIC.OS.
    • If you are booting a PortMaster 2 model PM-2, PM-2E, PM-2R, or PM-2ER from the network, move the GENERIC.OS file to /tftpboot/GENERIC.PM2.

    • If you are booting an IRX from the network, move the GENERIC.OS file to /tftpboot/GENERIC.IRX.

12. Set up TFTP on your boot host by entering the following commands:

    % umask 22 % mkdir /tftpboot % mv GENERIC.OS /tftpboot/GENERIC.OS % cd /tftpboot % ln -s . tftpboot

13. Using a text editor, uncomment the tftp command entry in the /etc/inetd.conf file.

    To have the inetd daemon reread the /etc/inetd.conf file, send a SIGHUP signal to the inetd process.

    This procedure applies to most UNIX systems. However, the procedure for enabling TFTP on your system might vary. Consult your system documentation.

14. Use one of the following commands on the console to boot the PortMaster:
    • To boot ComOS from the boot server using TFTP, enter the following command:

      > tftp Ipaddress

    Enter the IP address of the TFTP host that has the GENERIC.OS software.

    The PortMaster then boots using ComOS from the boot server. The new ComOS has not yet been loaded into the Flash RAM of your PortMaster.

    • To download the ComOS directly through the serial line, enter the following command:

      > download size

    Replace size with the number of bytes in the ComOS to be downloaded. The PortMaster then boots using the ComOS downloaded from the serial connection. The new ComOS has not yet been loaded into the Flash RAM of your PortMaster.

15. To install the new ComOS into the Flash RAM, run pminstall.

16. After the new ComOS is installed, prepare the PortMaster for operation by doing the following:

a. Turn off the power on the PortMaster.

b. Remove the terminal from the console port.

c. Return the DIP switches to their normal operating positions.

d. Turn on the power to reboot the PortMaster.

Resetting the Configuration to Factory Defaults

Warning ¯ Be careful when using the erase commands. You can remove the configuration and operating system from your PortMaster, which are difficult to restore.

You must reboot the PortMaster for the changes to take effect.

Command> set console Setting CONSOLE to port S0 Command> set debug 0x72 Setting debug value to 0x72 Command> erase configuration Erasing FLASH cell 2 - 28F010 ... Succeeded in 82 tries Successfully erased FLASH configuration

Note ¯ If you erase the configuration and reboot your PortMaster, it is set back to factory defaults. You are then required to connect a console to the S0 or C0 port for initial configuration.

Erasing and Reloading ComOS

Warning ¯ Be careful when using the erase commands. You can remove the configuration and operating system from your PortMaster, which are difficult to restore.

Command> set console Setting CONSOLE to port S0 Command> set debug 0x72 Setting debug value to 0x72 Command> erase comos Erasing FLASH cell 0 - 28F010 ... Succeeded in 75 tries Erasing FLASH cell 1 - 28F010 ... Succeeded in 78 tries Erasing FLASH cell 3 - 28F010 ... Succeeded in 69 tries sys_msginit: Missing System Messages Successfully erased ComOs

After you have erased ComOS, reload it by running the pminstall utility.

Note ¯ If you erase ComOS and reboot your PortMaster, you must to do a netboot to restore the operating system. See "Booting from the Network" on page 20-15 for instructions.

Erasing ComOS and the Configuration

Warning ¯ Be careful when using the erase commands. You can remove the configuration and operating system from your PortMaster, which are difficult to restore.

Command> set console Setting CONSOLE to port S0 Command> set debug 0x72 Setting debug value to 0x72 Command> erase all-flash Erasing FLASH cell 0 - 28F010 ... Succeeded in 72 tries Erasing FLASH cell 1 - 28F010 ... Succeeded in 76 tries Erasing FLASH cell 2 - 28F010 ... Succeeded in 76 tries Erasing FLASH cell 3 - 28F010 ... Succeeded in 66 tries sys_msginit: Missing System Messages Successfully erased all FLASH

After you have erased ComOS, reload it by running the pminstall utility.

Note ¯ If you erase ComOS and reboot your PortMaster, you must to do a netboot to restore the operating system. See "Booting from the Network" on page 20-15 for instructions.

Erasing Specific Files from the Configuration

Warning ¯ Be careful when using the erase commands. You can remove the configuration and operating system from your PortMaster, which are difficult to restore.

You can erase specific configuration files from the PortMaster. Use the show files command as follows for a list of files:

Command> show files File Name Length ---------------- ------- confdata 216 config 1750 snmp 18 filters 26 sapfilt 26 modem 2206 ------- Total 14242

To erase a specific file, use the following command:

Command> erase file String

Replace String with a filename from the show files command list.