In a Tx-Plus routing matrix, packets traverse both electrical and optical media as they travel between the Switch Interface Boards (SIBs) in the T1600 routing nodes (called ST-SIB-Ls) and the SIBs in the TX Matrix Plus platform (called F13SIBs and F2S-SIBs). The chassis process (chassisd) on the routing node that houses the indicated F13SIB detected the indicated error as packets that were traveling in the in the optical media from the indicated ST-SIB-L on the indicated LCC.
When a CHASSISD_FM_ERROR_F13_FB_RX_VC event occurs, a message similar to the following is reported:
chassisd: CHASSISD_FM_ERROR_F13_FB_RX_VC: LOS on F13SIB11_FBD VCSEL 2 Channel 0 connected from LCC 0 SIB_L 4
The cause is due to either the SIB or LCC being in a state that is creating an error condition in the communication between these units.
Examine the following outputs to help determine the cause of this message:
show log messages
show chassis alarms
show log chassisd
show chassis sibs
show chassis fabric sibs
show chassis fabric plane-location
show chassis fabric plane
show chassis fabric fpcs
show chassis fabric topology
Look for any related events that occurred at or just before the CHASSISD_FM_ERROR_F13_FB_RX_VC message in the syslog and chassisd outputs.
Perform these steps:
- During a maintenance window, as it will impact transit traffic, try offline/online cycling the associated SIB/LCC components. The cable between them should also be cleaned at this time.