Description

This KB provides information concerning the log message "cheetah_serdesbased_linkstatus:LOS detected port" seen on the EX3200 and EX4200 Switches.

Symptoms

Provide information on log message "cheetah_serdesbased_linkstatus:LOS detected port" seen on EX3200 and EX4200 Switches.

Solution

The log messages below can be seen on EX3200 and EX4200 Switches when SFP transceivers are installed in ports 0 & 2 only.  These messages are seen when an SFP transceiver is installed and configured as 1G setting, with no fiber/cable attached.  These messages are harmless.

Jul 27 21:29:06 fr01daer01 chas[693]: cheetah_serdesbased_linkstatus:LOS detected port:2 pic:0xf080
Jul 27 21:29:06 fr01daer01 chas[693]: cheetah_serdesbased_linkstatus:LOS detected port:0 pic:0xf080
Jul 27 21:29:06 fr01daer01 chas[693]: cheetah_serdesbased_linkstatus:LOS detected port:2 pic:0xf080
Jul 27 21:29:06 fr01daer01 chas[693]: cheetah_serdesbased_linkstatus:LOS detected port:0 pic:0xf080
Jul 27 21:29:06 fr01daer01 chas[693]: cheetah_serdesbased_linkstatus:LOS detected port:2 pic:0xf080

Workaround:
To stop these messages from being generated remove the transceivers that are not in use, or have no fiber/cable connected.

Solution:
This issue is fixed in JUNOS Software Releases 9.6R3, 10.0R1, 10.1R1, and above.