This article clarifies that the "ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2 " errors that may be seen on the SRX Series firewall and will not have any service impact if the number of correctable and uncorrectable is the same, and indicates what must be done to clear the error.

The following messages will appear in the log messages:

Sep 1 03:12:01 Labfirewall node1.fpc0 Cowra: XLP0 ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2  

Sep 1 03:12:02 Labfirewall node1.fpc0 Cowra: XLP0 ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2  

Sep 1 03:12:04 Labfirewall node1.fpc0 Cowra: XLP0 ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2   

The error checking and correction (ECC) process has the important function of error detection and recovery on RLDRAM. In this process, data is stored as 8 bits in RLDRAM block's cell blank, which is used to detect and correct 1-bit errors and detect double/multi-bit errors.

node1.fpc0 Cowra: XLP0 ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2 

If you look closely at the message log with the ECC error, you see that the number of uncorrectable and correctable errors is the same. If the number of uncorrectable and correctable errors is the same in the ECC error message, it means that the errors being detected can actually be corrected and are immediately corrected as well. Therefore, there will be no service impact due to these errors.

ECC error, chA 4183687697 8192 chB 0 0, correctable 2, uncorrectable 2 

There should not be any service impact due to this error. To clear this error, re-seat of the FPC card is required in the maintenance window. 

2023-09-06: First Draft of this article.