Bug ID 851733: Tcpdump messages (warning, error) are sent to stdout instead of stderr

Last Modified: Apr 17, 2024

Affected Product(s):
BIG-IP All(all modules)

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,,

Fixed In:

Opened: Nov 20, 2019

Severity: 1-Blocking


Tcpdump error and warning messages are sent to stdout. This causes issues when the packet capture is sent to a file, and standard programs such as Wireshark do not understand the error message strings and error.


Captures cannot be analyzed from the capture file


-- tcpdump used to capture packets. -- tcpdump stdout redirected to a file. -- The capture file is read by standard packet parse-and-display tools wuch as Wireshark .



Fix Information

Tcpdump messages are now sent to stderr. Packet dumps continue to be in stdout. A capture file contains only captured packets, and can be analyzed by any tool that understands pcap format (wuch as Wireshark, tshark etc.)

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips