Using CTRACE › Errors in Packets

Errors in Packets

Sometimes during the formatting of a packet trace, errors are found, such as invalid field values in packet headers. The Packet Trace facility cannot analyze these headers. It displays warning messages, in red, on the Packet List panel to inform you of these errors.

The warning messages relate to such things as:

• Incorrect lengths
• Invalid use of flags
• Invalid field values
• Reserved fields being used
• Invalid IP and TCP options
• Invalid checksums

View Packets in Error

To view packets in error for a trace

1. Enter /CTRACE.L at a prompt.

   The Saved Trace List appears.

2. Enter PE (IP Packets in Error) next to the trace entry you want to view.

   The IP Packets in Error List appears.

3. Enter S or D next to an error entry.

   A Formatted Packet Display of the packet in error appears.

Deal with Errors in Packets

If there are errors in the traced packets, do the following:

• See the appropriate RFC to determine the correct usage of fields in the protocol.
• Identify the device/program that is sending the invalid packets.
• Identify other IP devices that the packet traversed, as they may be corrupting the packet.
• Rectify the problem.