HP-UX Internet Services Administrator's Guide (May 2010)

— When using a nodal management utility?
— When transmitting data?
• Does the problem affect all users? The entire node? Has anything changed recently?
The possibilities are as follows:
— New software and hardware installation.
— Same hardware but changes to the software. Has the configuration file been
modified? Has the HP-UX configuration been changed?
— Same software but changes to the hardware. Do you suspect hardware or
software?
It is often difficult to determine whether the problem is hardware-related or
software-related. The symptoms of the problem that indicate you should suspect the
hardware are as follows:
• Intermittent errors.
• Network-wide problems after no change in software.
• Link-level errors, from logging subsystem, logged to the console.
• Data corruption—link-level trace that shows that data is sent without error but is
corrupt or lost at the receiver.
• Red light on the LAN card is lit, or yellow light on the X.25/800 card is lit.
Following are symptoms that would lead you to suspect the software:
• Network services errors returned to users or programs.
• Data corruption.
• Logging messages at the console.
Knowing what has recently changed on your network may also indicate whether the
problem is software-related or hardware-related.
Diagnostic Tools Summary
Table 5-1 describes the most frequently used diagnostic tools.
Table 5-1 Diagnostic Tools
DescriptionTool
A nodal management command that returns statistical information regarding
your network.
netstat
A diagnostic program that tests LAN connections between HP computers.
landiag
A diagnostic program that runs link-level loopback tests between HP systems.
linkloop uses IEEE 802.3 link-level test frames to check physical connectivity
with the LAN. This diagnostic tool is different from the loopback capability
of landiag because it tests only the link-level connectivity and not the
transport-level connectivity.
linkloop
76 Troubleshooting Internet Services