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Junos OS generates system log messages (also called syslog messages) to record events that occur on the device, including the following:

• Routine operations, such as creation of an Open Shortest Path First (OSPF) protocol adjacency or a user login to the configuration database.
• Failure and error conditions, such as failure to access a configuration file or unexpected closure of a connection to a peer process.
• Emergency or critical conditions, such as power-down of the device due to excessive temperature.

Each system log message identifies the Junos OS process responsible for generating the message and provides a brief description of the operation or error that occurred. For detailed information about specific system log messages, see the System Log Explorer.

To configure the device to log system messages, configure the syslog statement at the [edit system] hierarchy level.

In Junos OS Release 17.3R1, the syslog-event daemon handles the fxp0 in dedicated management routing instance for IPv4 addressed remote host. In Junos OS Release 18.1R1, the syslog-event daemon supports IPv6-based configuration when connecting to a remote host or an archival site and fxp0 is moved to dedicated management instance. In Junos OS Release 18.4R1, the syslog client can send messages through any routing instance that you define at appropriate hierarchies. See routing-instance (Syslog).

Note:

This topic describes system log messages for Junos OS processes and libraries and not the system logging services on a Physical Interface Card (PIC) such as the Adaptive Services PIC.

In Junos OS Evolved, each node has the standard

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

5 tool, which is an interface to retrieve and filter the system journal. System log messages are extracted from the system journal. The

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

6 process runs on all nodes and retrieves events (based on the syslog configuration) from the system journal as well as error messages from the different applications and forwards them to the

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

7 process. The

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

7 process runs on the primary Routing Engine and writes the log messages and errors to disk.

Use the System Log Explorer application to view or compare system log messages in different releases.

In Junos OS Evolved there is no

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

9 file on the backup Routing Engine. All backup Routing Engine logs are in the

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

9 file on the primary Routing Engine node.

By default, Junos OS Evolved appends the node name to the hostname in system log messages; Junos OS does not. This action keeps Junos OS Evolved system log messages compliant with RFC5424. However, some monitoring systems may not identify a Junos OS Evolved hostname correctly, because the hostname-node name combination does not match any hostnames in the inventory of hostnames.

Starting in Junos OS Evolved Release 20.4R2, to ensure accurate identification of Junos OS Evolved hostnames in your monitoring system, use the

[edit system syslog] host hostname {

facility-override facility;

}

1 configuration mode command. This command changes the format of the Junos OS Evolved system log messages. The node name is prepended to the process name in the message rather than appended to the hostname, thereby allowing the monitoring system to identify the hostname correctly.

For example, Junos OS system log messages do not print the origin process in system log messages coming from an FPC:

user@mxhost> show log messages Dec 19 13:22:41.959 mxhost chassisd[5290]: CHASSISD_IFDEV_DETACH_FPC: ifdev_detach_fpc(0) Dec 19 13:23:22.900 mxhost fpc2 Ukern event counter Sock_tx init delayed

However, Junos OS Evolved messages append the node name to the hostname and do print the origin process for messages coming from a node, including FPCs:

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost*-re0* mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost*-fpc0* evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost*-fpc1* evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost*-re0* ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

If you have configured the alternate format for Junos OS Evolved system log messages, the same set of system log messages would look like this instead, with the hostname by itself:

user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost re0- mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost fpc0- evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost fpc1- evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost re0- ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd

Starting in Junos OS Release 22.1R1 on SRX Series and NFX Series devices and Junos OS Evolved Release 22.2R1 on QFX5130, QFX5200, QFX5220, and QFX5700 devices, we’ve added multiple events inside the event tag using the

[edit system syslog] host hostname {

facility-override facility;

}

2 format, which has an option (

[edit system syslog] host hostname {

facility-override facility;

}

3. to separate the events and to generate system log messages. Earlier to these releases, the event tag used the

[edit system syslog] host hostname {

facility-override facility;

}

4 format and for various combinations of

[edit system syslog] host hostname {

facility-override facility;

}

5 filters was not getting logged.

System Logging Facilities and Message Severity Levels

lists the Junos OS system logging facilities that you can specify in configuration statements at the

[edit system syslog] host hostname {

facility-override facility;

}

6 hierarchy level.

Table 1: Junos OS System Logging Facilities

Facility (number)

Type of Event or Error

[edit system syslog] host hostname {

facility-override facility;

}

7 (0)

The Junos OS kernel performs actions and encounters errors.

[edit system syslog] host hostname {

facility-override facility;

}

8 (1)

User-space perform actions or encounter errors.

[edit system syslog] host hostname {

facility-override facility;

}

9 (3)

System perform actions or encounter errors.

[edit system syslog] file filename {

structured-data;

}

0 (4)

Authentication and authorization attempts.

[edit system syslog] file filename {

structured-data;

}

1 (11)

FTP performs actions or encounters errors.

[edit system syslog] file filename {

structured-data;

}

2 (12)

Network Time Protocol performs actions or encounters errors.

[edit system syslog] file filename {

structured-data;

}

3 (13)

Security related events or errors.

[edit system syslog] file filename {

structured-data;

}

4 (17)

Events related to dynamic flow capture.

[edit system syslog] file filename {

structured-data;

}

5 (18)

The local external applications perform actions or encounter errors.

[edit system syslog] file filename {

structured-data;

}

6 (19)

The firewall filter performs packet filtering actions.

[edit system syslog] file filename {

structured-data;

}

7 (20)

The Packet Forwarding Engine performs actions or encounters errors.

[edit system syslog] file filename {

structured-data;

}

8 (21)

Specified configuration is invalid on the router type.

[edit system syslog] file filename {

structured-data;

}

9 (22)

Changes to the Junos OS configuration.

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

0 (23)

A client application such as a Junos XML protocol or NETCONF XML client issues commands at the Junos OS command-line interface (CLI) prompt.

lists the severity levels that you can specify in configuration statements at the

[edit system syslog] host hostname {

facility-override facility;

}

6 hierarchy level. The levels from

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

2 through

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

3 are in the order from highest severity (greatest effect on functioning) to lowest.

Unlike the other severity levels, the

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

4 level disables logging of a facility instead of indicating how seriously a triggering event affects routing functions. For more information, see .

Table 2: System Log Message Severity Levels

Value

Severity Level

Description

N/A

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

4

Disables logging of the associated facility to a destination.

0

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

2

System panic or other condition that causes the router to stop functioning.

1

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

7

Conditions that require immediate correction, such as a corrupted system database.

2

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

8

Critical conditions, such as hard errors.

3

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

9

Error conditions that generally have less serious consequences than errors at the emergency, alert, and critical levels.

4

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

0

Conditions that warrant monitoring.

5

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

1

Conditions that are not errors but might warrant special handling.

6

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

3

Events or non-error conditions of interest.

7

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

3

Includes all severity levels.

Default System Log Settings

summarizes the default system log settings that apply to all routers that run the Junos OS and specifies which statement to include in the configuration to override the default value.

Table 3: Default System Logging Settings

Setting

Default

Overriding Statement

Instructions

Alternative facility for message forwarded to a remote machine

For

[edit system syslog] file filename {

structured-data;

}

9:

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

5

For

[edit system syslog] file filename {

structured-data;

}

8:

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

7

For

[edit system syslog] file filename {

structured-data;

}

4:

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

9

For

[edit system syslog] file filename {

structured-data;

}

6:

[edit system syslog] time-format format;

1

For

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

0:

[edit system syslog] time-format format;

3

For

[edit system syslog] file filename {

structured-data;

}

7:

[edit system syslog] time-format format;

5

[edit system syslog] host hostname {

facility-override facility;

}

Format of messages logged to a file

Standard Junos OS format, based on UNIX format

[edit system syslog] file filename {

structured-data;

}

Maximum number of files in the archived set

10

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

Maximum size of the log file

M Series, MX Series, and T Series: 1 megabyte (MB)

TX Matrix: 10 MB

[edit system syslog] archive {

size size;

} file filename {

archive {
    size size;
}

}

Timestamp format

Month, date, hour, minute, second

For example:

[edit system syslog] time-format format;

6

[edit system syslog] time-format format;

Users who can read log files

[edit system syslog] time-format format;

7 user and users with the Junos OS

[edit system syslog] time-format format;

8 permission

[edit system syslog] archive {

world-readable;

} file filename {

archive {
    world-readable;
}

}

Platform-Specific Default System Log Messages

The following messages are generated by default on specific routers. To view any of these types of messages, you must configure at least one destination for messages as described in .

• To log the kernel process message on an M Series, MX Series, or T Series router, include the [edit system syslog] time-format format; 9 statement at the appropriate hierarchy level: [edit system syslog] (console | file filename | host destination | user username) {

  kernel info;  
  

  }
• On a routing matrix composed of a TX Matrix router and T640 routers, the primary Routing Engine on each T640 router forwards all messages with a severity of [edit system syslog] archive {

  files number;  
  

  } file filename {

  archive {  
      files number;  
  }  
  

  } 3 and higher to the primary Routing Engine on the TX Matrix router. This is equivalent to the following configuration statement included on the TX Matrix router: user@ptxhost-re0> show log messages May 25 18:41:05.375 ptxhost*-re0* mgd[16201]: UI_CHILD_STATUS: Cleanup child '/usr/sbin/dot1xd', PID 21322, status 0 May 25 18:42:34.632 ptxhost*-fpc0* evo-cda-bt[14299]: Register bt.igp_misc.debug.hdr_length_cnt not found May 25 18:42:34.753 ptxhost*-fpc1* evo-cda-bt[14427]: HBM: hbm_gf_register_inst May 25 18:47:14.498 ptxhost*-re0* ehmd[5598]: SYSTEM_APP_READY: App is ready re0-ehmd 0

Starting in Junos OS Release 15.1X49-D10 and Junos OS Release 17.3R1, likewise on a routing matrix composed of a TX Matrix Plus router with connected T1600 or T4000 routers, the primary Routing Engine on each T1600 or T4000 LCC forwards to the primary Routing Engine on the TX Matrix Plus router all messages with a severity of

[edit system syslog] archive {

files number;

} file filename {

archive {
    files number;
}

}

3 and higher.