The ICHIP is reporting a fabric related error in a traffic stream for troubleshooting purposes. This may or may not indicate traffic loss, which would need to be verified by further examination of other fabric counters.
The problem related to this syslog message is described in the following sections:
The “first cell drops in ichip” message is logged each time the ICHIP reports a fabric issue in the first cell of a traffic stream.
When a “first cell drops in ichip” event occurs, a message similar to the following is reported:
fpc4 ICHIP(0)_REG_ERR:first cell drops in ichip fi rord : %PFE-3: 178
fpc2 ICHIP(0)_REG_ERR:first cell drops in ichip fi rord : %PFE-3: 181
fpc1 ICHIP(0)_REG_ERR:first cell drops in ichip fi rord : 597
fpc4 ICHIP(2)_REG_ERR:first cell drops in ichip fi rord : 1
The cause is due to the ICHIP detecting a cell drop at the start of a traffic stream in the fabric. The log message is generated to assist in troubleshooting of possible fabric issues, which would have to be verified elsewhere. This does not mean there is a problem with the ICHIP, as it is only reporting a fabric state. It also does not mean that transit traffic is being dropped. The cell drop can be due to hardware or software being in a state that creates the drop, or excessive traffic through the Packet Forwarding Engine.
Examine the following output to help determine the cause of this message:
show log messages
show log chassisd
show chassis fabric fpcs
show chassis fabric map
show chassis fabric summary
show chassis fabric plane
show chassis fabric plane-location
show chassis environment cb
show pfe statistics traffic
start shell pfe network fpc[num]
show ichip [num] errors
show ichip [num] f statistics
show ichip [num] f statistics fab_stream
show ichip [num] wi seg errors fab_stream [num]
show pfe statistics error | no-more <== Please take this output 3 times, 30 seconds apart.
Look for any related events that occurred at or just before the “first cell drops in ichip” message in the log messages and log chassisd outputs.
Perform these steps:
1. If the cell drop occurred at about the same time any of the following events occurred, then this is expected and can be ignored:
- An FPC was placed offline or online.
- A Routing Engine Mastership switch occurred.
- Commit was done.
- ISSU was in progress.
- Router was powering up or rebooting.
2. During a maintenance window, as it will impact transit traffic, try resetting the reporting FPC by placing it offline, and then online again.
3. If the log messages continue, open a case with your technical support representative to investigate the issue further.