Troubleshooting the IP Switch Processor


Problems logging into or accessing the unit

Not able to log into the console port and do not see any error messages

Possible problems:

Note:A good way of verifying your terminal setup is to connect to a different computer and ensure that you can talk to it. Using a terminal emulation program, laptops or terminals should be able to talk back to back in the same manner as the terminal would communicate with the IP Switch Processor. If this is not possible, the problem is with the terminal or cable and not with the IP Switch Processor

Get a Login Prompt, but will not accept password

Possible problems:

Procedure for overwriting the passwords

Note: This can only be done with local access to the unit

1. Connect a VT-100 terminal or PC running a VT-100 emulation program into the console port.

2. Boot up in single user mode: To do this reboot or power cycle the machine, When you see the line " boot: " you must enter "-s" before it goes into multiuser mode. (you have about 10 seconds)

3. It will then continue to boot in single user mode. After several lines you will get the following message

'Enter pathname of shell or RETURN for sh: ' (Hit return at this point)

  1. Use the /etc/overpw command to enter new passwords. Below is an example:
# /etc/overpw
After entering the new passwords type 'reboot'

Procedure for defaulting the database

Note: This will overwrite the entire database with the factory defaults and bring the unit up in a mode where it will ask for hostname, passwords, and interface information.

  1. Log into the unit as user admin
  2. Use command /etc/unconfig (This will overwrite the configuration database!)
  3. Reboot the system. It will now boot as it did upon delivery.

Do not get a login prompt and error messages are displayed

Possible problems:

Caution: The procedure below can be used to install a system from scratch, however this will completely replace the contents of the drive and may be needed to restore or reload a unit. You should save any valuable configuration information before proceeding.

See the download instructions thatcontain the full install procedure.

Not able to connect to the local unit with a browser, but console access works

Possible problems:


General Interface Problems

Do not see interfaces that should be present

Possible problems: Local IP Switch Processor ports do not show up

Possible problems: ATM1600 Switch ports do not show up

Possible Problems: FAS1200 ports do not show up but atm1600 ATM port does show up

Common Ethernet problems (Connectivity problems with attached device.)

Possible problems:

Common ATM Interface problems

Possible problems:


Common Connectivity Problems (Interfaces look good but not able to ping.)

Unable to Ping through unit (No connectivity between ports.)

Note: This section assumes that the user has localized the problem by issuing pings to various network interfaces so that the problem is within a router or network

Troubleshooting routing Problems

Common Problems with OSPF

Common Problems with RIP

Common problems exchanging routes

Problems with Multicast

Possible problems

Problems interfacing to 1483 devices (Classical IP)

Possible problems


Problems upgrading a unit

Possible problems


TCP Dump command (Viewing packets on a interface)

tcpdump:

Tcpdump is a program provided with the Ipsilon software which is very much like the tcpdump or snoop programs of a UNIX workstation. Tcpdump is used to see the traffic on a network, not to alter it. The information below contains some important features and commands that are used with tcpdump. For further information see the man page for tcpdump

tcpdump defaults to lowest number port:

control-c will stop tcpdump.

tcpdump -i <interface name> does tcpdump per specific interface

Example:

tcpdump -i atm-s3p1c0

or for switch port from controller

tcpdump -i atm-s1p1c0s3p1c0

tcpdump -i <interfce name> proto <well known protocol name>

Example:

tcpdump -i eth-s2p3c0 proto ospf

will only show ospf on that interface

tcpdump -i eth-s2p1c0 proto igrp

will show only the igrp traffic on that wire.

tcpdump -i <interface name> port <UNIX application port>

Example:

tcpdump -i eth-s1p1c0 port telnet

or tcpudmp -i eth-s1p1c0 port 23

will show all telnet traffic

tcpdump -i <interfce name> <ip or udp> <UNIX application port>

can specify ip or udp port

Example:

tcpdump -i eth-s2p1c0 udp port 68

will show all bootp/dhcp traffic.

tcpdump -i <interface name> <ip or udp> <not> <UNIX application port>

How to filter traffic

Example:

tcpdump -i eth-s1p1c0 not port 80

will not show WWW traffic on that interfce

tcpdump -i <interface name> -s <packet size> -vv

How to specify how much of the packet to view

Example:

tcpdump -i eth-s1p1c0 -s 320 -vv

will recieve 320 bytes of packet, more decode will be done

Saving a trace to a file:

A trace file may be generated by using the tcpdump program and giving the -w flag. This copies the packet to a file on the hard-drive of the unit. This can then be used to mail back to Ipsilon Support, or moved to another computer where tcpdump can be used to view that file. NOTE1: this copies the first 68 bytes of every packet, unless the capture size is increased. For users running without data encryption, passwords are also copied into this file. NOTE2: if the network being snooped is busy this file will grow quite fast. It is usually a good idea to create this file on the /usr partition, since it is largest. (Remember to delete this file.)

Example:

tcpdump -i eth-s1p1c0 -w /usr/trace.file

Will not display packets, doing a control-c will end the capture and print how many Packets were captured

RIP example:

tcpdump -i eth-s1p1c0 -s 320 -vv port 520

will show all RIP traffic on the network attached to eth-s1p1c0

port 520 is also the port used by 'routed' on UNIX workstations.

OSPFexample:

tcpdump -i atm-s3p1c0 -s 320 -vv proto ospf

will show all OSPF traffic on the atm link, including LSA's and full information on routs.

IGRP example:

tcpdump -i eth-s1p1c0 -s 320 -vv proto igrp

will show all IGRP traffic on the network connected to eth-s1p1c0.

Telnet example:

tcpdump -i eth-s1p1c0 port 23

will show all telnet traffic on network connected to eth-s1p1c0.