Concept Guide

The panic string contains key information regarding the crash. Several panic string types exist, and they are displayed in regular English text
to enable easier understanding of the crash cause.
Example of Application Mini Core Dump Listings
DellEMC#dir flash:/CORE_DUMP_DIR
Directory of flash:/CORE_DUMP_DIR
1 drwx 4096 Jan 07 2015 13:25:04 +00:00 .
2 drwx 4096 Jan 01 1980 00:00:00 +00:00 ..
3 drwx 4096 Jan 07 2015 13:25:04 +00:00 FTP_STK_MEMBER
4 -rwx 512 May 11 2015 20:54:24 +00:00 f10StkUnit.kcore.mini.txt
flash: 2368282624 bytes total (2293637120 bytes free)
Example of a Mini Core Text File
VALID MAGIC
-----------------PANIC STRING -----------------
panic string is :<null>
---------------STACK TRACE START---------------
0035d60c <f10_save_mmu+0x120>:
00274f8c <panic+0x144>:
0024e2b0 <db_fncall+0x134>:
0024dee8 <db_command+0x258>:
0024d9c4 <db_command_loop+0xc4>:
002522b0 <db_trap+0x158>:
0026a8d0 <mi_switch+0x1b0>:
0026a00c <bpendtsleep>:
----------------STACK TRACE END----------------
--------------------FREE MEMORY---------------
uvmexp.free = 0x2312
Enabling TCP Dumps
A TCP dump captures CPU-bound control plane trac to improve troubleshooting and system manageability. When you enable TCP dump,
it captures all the packets on the local CPU, as specied in the CLI.
You can save the trac capture les to ash, FTP, SCP, or TFTP. The les saved on the ash are located in the ash://TCP_DUMP_DIR/
Tcpdump_<time_stamp_dir>/ directory and labeled tcpdump_*.pcap. There can be up to 20 Tcpdump_<time_stamp_dir> directories. The
21st le overwrites the oldest saved le. The maximum le size for a TCP dump capture is 1MB. When a le reaches 1MB, a new le is
created, up to the specied total number of les.
Maximize the number of packets recorded in a le by specifying the snap-length to capture the le headers only.
The tcpdump command has a nite run process. When you enable the tcpdump command, it runs until the capture-duration timer and/or
the packet-count counter threshold is met. If you do not set a threshold, the system uses a default of a 5 minute capture-duration and/or a
single 1k le as the stopping point for the dump.
You can use the capture-duration timer and the packet-count counter at the same time. The TCP dump stops when the rst of the
thresholds is met. That means that even if the duration timer is 9000 seconds, if the maximum le count parameter is met rst, the dumps
stop.
To enable a TCP dump, use the following command.
• Enable a TCP dump for CPU bound trac.
CONFIGURATION mode
tcpdump cp [capture-duration time | filter expression | max-file-count value | packet-count
value | snap-length value | write-to path]
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Debugging and Diagnostics