Description

This article explains the reason and impact of the following kernel syslog messages:  

​Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pic_listener_connect: conn established: mgmt addr=0x6000000,
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: if_pfe_peek_peer_info: Invalid IPC message subtype : 54
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pfe_listener_common_task: Error. Socket 0xda8ee338 closed.
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pic_listener_connect: conn established: mgmt addr=0x6000000,
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: if_pfe_peek_peer_info: Invalid IPC message subtype : 54
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pfe_listener_common_task: Error. Socket 0xda8ee4d4 closed.

Solution

During Junos upgrade, when the two routing-engines are on different Junos versions briefly, the following messages are seen:  

Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pic_listener_connect: conn established: mgmt addr=0x6000000,
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: if_pfe_peek_peer_info: Invalid IPC message subtype : 54
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pfe_listener_common_task: Error. Socket 0xda8ee338 closed.
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pic_listener_connect: conn established: mgmt addr=0x6000000,
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: if_pfe_peek_peer_info: Invalid IPC message subtype : 54
Mar 20 06:20:04 2020  re1-jtac-mx /kernel: pfe_listener_common_task: Error. Socket 0xda8ee4d4 closed.

Notice the 'mgmt addr' that is for RE1 in this case. The PIC establishes a connection with the RE, but as the RE1 is on a different Junos version than the primary RE0, the IPC (Inter process communication) messages that the PFE receives from the RE do not make sense, and are treated as invalid. Eventually, the socket connection is closed.

In some cases, along with these log messages, you can find any protocol stuck in "In progress" state as well in the "show task replication" CLI output. This is again due to replication errors between the two REs, owing to the difference in Junos versions.

These log messages are not impacting and are no longer seen once both the REs are on the same Junos version.