Tracing Static Subscriber Events for Troubleshooting
The Junos OS trace feature tracks static subscriber operations and records events in a log file. The error descriptions captured in the log file provide detailed information to help you solve problems.
By default, nothing is traced. When you enable the tracing operation, the default tracing behavior is as follows:
Important events are logged in a file located in the
/var/log
directory. By default, the router uses the filenamejsscd
. You can specify a different filename, but you cannot change the directory in which trace files are located.When the trace log file
filename
reaches 128 kilobytes (KB), it is compressed and renamedfilename.0.gz
. Subsequent events are logged in a new file calledfilename
, until it reaches capacity again. At this point,filename.0.gz
is renamedfilename.1.gz
andfilename
is compressed and renamedfilename.0.gz
. This process repeats until the number of archived files reaches the maximum file number. Then the oldest trace file—the one with the highest number—is overwritten.You can optionally specify the number of trace files to be from 2 through 1000. You can also configure the maximum file size to be from 10 KB through 1 gigabyte (GB). (For more information about how log files are created, see the System Log Explorer.)
By default, only the user who configures the tracing operation can access log files. You can optionally configure read-only access for all users.
The following topics describe how to configure all aspects of tracing static subscriber operations:
Configuring the Static Subscribers Trace Log Filename
By default, the name of the file that records trace output
for static subscribers is jsscd
. You can specify a different
name with the file
option.
To configure the filename for static subscribers tracing operations:
Specify the name of the file used for the trace output.
[edit system processes static-subscribers traceoptions] user@host# set file stat-subs_1
Configuring the Number and Size of Static Subscribers Log Files
You can optionally specify the number of compressed, archived trace log files to be from 2 through 1000. You can also configure the maximum file size to be from 10 KB through 1 gigabyte (GB); the default size is 128 kilobytes (KB).
The archived files are differentiated by a suffix in the format .number.gz
. The newest archived file is .0.gz
and the oldest archived file is .(maximum
number)-1.gz
. When the current trace log file reaches
the maximum size, it is compressed and renamed, and any existing archived
files are renamed. This process repeats until the maximum number of
archived files is reached, at which point the oldest file is overwritten.
For example, you can set the maximum file size to 2 MB, and
the maximum number of files to 20. When the file that receives the
output of the tracing operation, filename
, reaches 2 MB, filename
is
compressed and renamed filename.0.gz
, and a new file called filename
is
created. When the new filename
reaches
2 MB, filename.0.gz
is renamed filename.1.gz
and filename
is compressed and renamed filename.0.gz
. This process repeats until there are 20 trace files.
Then the oldest file, filename.19.gz
, is simply overwritten when the next oldest file, filename.18.gz
is compressed and renamed to filename.19.gz
.
To configure the number and size of trace files:
Specify the name, number, and size of the file used for the trace output.
[edit system processes static-subscribers traceoptions] user@host# set file stat-subs_1 _logfile_1 files 20 size 2097152
Configuring Access to the Static Subscribers Log File
By default, only the user who configures the tracing operation can access the log files. You can enable all users to read the log file and you can explicitly set the default behavior of the log file.
To specify that all users can read the log file:
Configure the log file to be world-readable.
[edit system processes static-subscribers traceoptions] user@host# set file stat-subs_1 _logfile_1 world-readable
To explicitly set the default behavior, only the user who configured tracing can read the log file:
Configure the log file to be no-world-readable.
[edit system processes static-subscribers traceoptions] user@host# set file stat-subs_1 _logfile_1 no-world-readable
Configuring a Regular Expression for Static Subscriber Messages to Be Logged
By default, the trace operation output includes all messages relevant to the logged events.
You can refine the output by including regular expressions to be matched.
To configure regular expressions to be matched:
Configure the regular expression.
[edit system processes static-subscribers traceoptions] user@host# set file stat-subs_1 _logfile match regex
Configuring the Static Subscribers Tracing Flags
By default, only important events are logged. You can specify which events and operations are logged by specifying one or more tracing flags.
To configure the flags for the events to be logged:
Configure the flags.
[edit system processes static-subscribers traceoptions] user@host# set flag authentication
Configuring the Severity Level to Filter Which Static Subscriber Messages Are Logged
The messages associated with a logged event are categorized
according to severity level. You can use the severity level to determine
which messages are logged for the event type. The severity level that
you configure depends on the issue that you are trying to resolve.
In some cases you might be interested in seeing all messages relevant
to the logged event, so you specify all
or verbose
. Either choice generates a large amount of output. You can specify
a more restrictive severity level, such as notice
or info
to filter the messages . By default, the trace operation
output includes only messages with a severity level of error
.
To configure the type of messages to be logged:
Configure the message severity level.
[edit system processes static-subscribers traceoptions] user@host# set level severity