This article describes the occurrence of the syslog message “CMLC: Going disconnected; Routing engine chassis socket closed abruptly” and explains whether any action must be taken.

The following error may be seen in syslog:

%PFE-0: Going disconnected; Routing engine chassis socket closed abruptly
Sep 28 21:49:01 root-re1 (FPC Slot 6, PIC Slot 2) CMLC: %PFE-0: Going disconnected; Routing engine chassis socket closed abruptly

These messages are from the Flexible PIC Concentrators (FPCs) and are informational only. 

When you trigger a switchover, all the Packet Forwarding Engine (PFE) peers that are connected to the current primary are disconnected (the socket is closed and a timeout set for those PFE peers to reconnect to the new primary) and then they are re-connected to the new primary by creating a new socket.

The messages stating that the socket closed abruptly that you see are from the PFE or the FPC or the CMLC. They are seen on the old primary or the new primary, depending on the PFE peers' re-connect time. If the PFE peers get connected to the new primary immediately, the messages are seen on the new primary, which can be ignored.

No action is required in the graceful Routing Engine switchover (GRES) context because these messages are expected by design. The messages would appear at least once when a switchover is performed.

However, in a non-GRES context, a connection drop indicates a problem and must be investigated further.

2020-10-19: Article reviewed for accuracy; no changes required.

2025-11-27: added SRX