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traceoptions (Next Gen Services Service-Set Flow)


Hierarchy Level


Configure flow tracing options for a service-set.



Configure the trace file options.


Name of the file to receive the output of the tracing operation. Enclose the name within quotation marks. All files are placed in the directory /var/log. By default, the name of the file is the name of the process being traced.

files number

Maximum number of trace files. When a trace file named trace-file reaches its maximum size, it is renamed to trace-file.0, then trace-file.1, and so on, until the maximum number of trace files is reached. The oldest archived file is overwritten.

If you specify a maximum number of files, you also must specify a maximum file size with the size option and a filename.

  • Range: 2 through 1000 files

  • Default: 10 files

match regular-expression

Refine the output to include lines that contain the regular expression.

size maximum-file-size

Maximum size of each trace file, in kilobytes (KB), megabytes (MB), or gigabytes (GB). When a trace file named trace-file reaches this size, it is renamed trace-file.0. When the trace-file again reaches its maximum size, trace-file.0 is renamed trace-file.1 and trace-file is renamed trace-file.0. This renaming scheme continues until the maximum number of trace files is reached. Then the oldest trace file is overwritten.

If you specify a maximum file size, you also must specify a maximum number of trace files with the files option and a filename.

Syntax: x K to specify KB, x m to specify MB, or x g to specify GB

  • Range: 0 KB through 1 GB

  • Default: 128 KB

world-readable | no-world-readable

By default, log files can be accessed only by the user who configures the tracing operation. The world-readable option enables any user to read the file. To explicitly set the default behavior, use the no-world-readable option.


Trace operation to perform. To specify more than one trace operation, include multiple flag statements.


Trace with all flags enabled


Trace basic packet flow activity


Trace IP fragmentation and reassembly events


Trace flow high-availability information


Trace flow host traffic information


Trace multicast flow information


Trace route lookup information


Trace session creation and deletion events


Trace session scan information


Trace TCP packet flow information


Trace tunnel information


Set remote tracing as disabled.

packet-filter filter-name

Packet filter to enable during the tracing operation. Configure the filtering options.

destination-port port-identifier

Match TCP/UDP destination port

destination-prefix address

Destination IP address prefix

interface interface-name

Logical interface

protocol protocol-identifier

Match IP protocol type

source-port port-identifier

Match TCP/UDP source port

source-prefix address

Source IP address prefix

rate-limit messages-per-second

Limit the incoming rate of trace messages.


Set the level for trace logging. This option is available only when the flag is set.


Trace key flow information, such as message types sent between SPU and central point, policy match, and packet drop reasons.


Trace extensive flow information, such as detailed information about sessions and fragments. Detail is the default level.


Trace error information, such as system failure, unknown message type, and packet drop.

Required Privilege Level

trace—To view this in the configuration.

trace-control—To add this to the configuration.

Release Information

Statement introduced in Junos OS Release 20.3R1.