Trace SNMP Script Processing on Devices Running Junos OS
SNMP script tracing operations track SNMP script operations and record them in a log file. The logged error descriptions provide detailed information to help you solve problems faster.
The default operation of SNMP script tracing is to log important events, which include errors, warnings, progress messages, and script processing events, in the /var/log/snmp.log file on the device. When the file snmp.log reaches 128 kilobytes (KB), it is renamed with a number 0 through 9 (in ascending order) appended to the end of the file and then compressed. The resulting files are snmp.log.0.gz, then snmp.log.1.gz, until there are 10 trace files. Then the oldest trace file (snmp.log.9.gz) is overwritten.
Minimum Configuration for Enabling Traceoptions for SNMP Scripts
If no SNMP script trace options are configured, the simplest
way to view the trace output of an SNMP script is to configure the output trace flag and issue the show log snmp.log | last command. To do this, perform the following steps:
If you have not done so already, enable an SNMP script by including the
filestatement at the[edit system scripts snmp]hierarchy level.[edit system scripts snmp] user@host# set file filename oid oid
Enable trace options by including the
traceoptions flag outputstatement at the[edit system scripts snmp]hierarchy level.[edit system scripts snmp] user@host# set traceoptions flag output
Commit the configuration.
[edit] user@host# commit
To display the resulting trace messages recorded at the end of the /var/log/snmp.log file, issue the
show log snmp.log | lastoperational mode command.[edit] user@host# run show log snmp.log | last
Table 1 summarizes useful
filtering commands that display selected portions of the snmp.log file.
Task |
Command |
|---|---|
Display logging data associated with all SNMP script processing. |
|
Display processing for only the most recent operation. |
|
Display processing for script errors. |
|
Display processing for a particular script. |
|
Example: Minimum Configuration for Enabling Traceoptions for SNMP Scripts
Display the trace output of the SNMP script file sample_snmp.slax in the default SNMP script log file:
[edit]
system {
scripts {
snmp {
file sample_snmp.slax {
oid .1.3.6.1.4.1.2636.13.61.1.9.1.1;
}
traceoptions {
flag output;
}
}
}
[edit] user@host# commit and-quit
user@host> show snmp mib get .1.3.6.1.4.1.2636.13.61.1.9.1.1.1 juniperMIB.13.61.1.9.1.1.1 = 211 user@host> show log snmp.log | last Mar 1 11:00:09 snmp script processing begins Mar 1 11:00:09 running snmp script 'sample_snmp.slax' Mar 1 11:00:09 opening snmp script '/var/run/scripts/snmp//sample_snmp.slax' Mar 1 11:00:09 snmp script input Mar 1 11:00:09 begin dump <?xml version="1.0" standalone="yes"?> <snmp-script-input> <snmp-action>get</snmp-action> <snmp-oid>.1.3.6.1.4.1.2636.13.61.1.9.1.1.1</snmp-oid> </snmp-script-input> Mar 1 11:00:09 end dump Mar 1 11:00:09 reading snmp script 'sample_snmp.slax' Mar 1 11:00:09 snmp script output Mar 1 11:00:09 begin dump <?xml version="1.0"?> <snmp-script-results> <snmp-oid>.1.3.6.1.4.1.2636.13.61.1.9.1.1.1</snmp-oid> <snmp-type>Integer32</snmp-type> <snmp-value>211</snmp-value> </snmp-script-results> Mar 1 11:00:09 end dump Mar 1 11:00:09 inspecting snmp output 'sample_snmp.slax' Mar 1 11:00:09 sample_snmp.slax triggered for oid = .1.3.6.1.4.1.2636.13.61.1.9.1.1.1, with type = Integer32, and with value = 211 Mar 1 11:00:09 finished snmp script 'sample_snmp.slax' Mar 1 11:00:09 snmp script processing ends
Configuring Tracing of SNMP Scripts
You cannot change the directory (/var/log) to which trace files are written. However, you can customize other
trace file settings by including the following statements at the [edit system scripts snmp traceoptions] hierarchy level:
[edit system scripts snmp traceoptions] file <filename> <files number> <size size> <world-readable | no-world-readable>; flag all; flag events; flag input; flag offline; flag output; flag rpc; flag xslt; no-remote-trace;
These statements are described in the following sections:
- Configuring the SNMP Script Log Filename
- Configuring the Number and Size of SNMP Script Log Files
- Configuring Access to SNMP Script Log Files
- Configuring the SNMP Script Trace Operations
Configuring the SNMP Script Log Filename
By default, the name of the file that records trace output is snmp.log. You can specify a different name by including
the file statement at the [edit system scripts snmp
traceoptions] hierarchy level.
[edit system scripts snmp traceoptions] file filename;
Configuring the Number and Size of SNMP Script Log Files
By default, when the trace file reaches 128 KB in size, it is renamed and compressed to filename.0.gz, then filename.1.gz, and so on, until there are 10 trace files. Then the oldest trace file (filename.9.gz) is overwritten.
You can configure the limits on the number and size of trace
files by including the following statements at the [edit system scripts snmp
traceoptions file filename] hierarchy
level:
[edit system scripts snmp traceoptions file filename] files number size size;
For example, set the maximum file size to 640 KB and the maximum number of files to 20. When the file that receives the output of the tracing operation (filename) reaches 640 KB, it is renamed and compressed to filename.0.gz, and a new file called filename is created. When filename reaches 640 KB, filename.0.gz is renamed filename.1.gz, and filename is renamed and compressed to filename.0.gz. This process repeats until there are 20 trace files. Then the oldest file (filename.19.gz) is overwritten.
The number of files can range from 2 through 1000 files. The file size can range from 10 KB through 1 gigabyte (GB).
If you set either a maximum file size or a maximum number of trace files, you also must specify the other parameter and a filename.
Configuring Access to SNMP Script Log Files
By default, access to the SNMP script log file is restricted
to the owner. You can manually configure access by including the world-readable or no-world-readable statement at
the [edit system scripts snmp traceoptions file filename] hierarchy level.
[edit system scripts snmp traceoptions file filename] (world-readable | no-world-readable);
The no-world-readable statement restricts SNMP script
log access to the owner. The world-readable statement enables
unrestricted access to the SNMP script log file.
Configuring the SNMP Script Trace Operations
By default, the traceoptions events flag is turned
on, regardless of the configuration settings, and only important events
are logged. This includes errors, warnings, progress messages, and
script processing events. You can configure the trace operations to
be logged by including the following statements at the [edit
system scripts snmp traceoptions] hierarchy level:
[edit system scripts snmp traceoptions] flag all; flag events; flag input; flag offline; flag output; flag rpc; flag xslt;
Table 2 describes the meaning of the SNMP script tracing flags.
|
Flag |
Description |
Default Setting |
|---|---|---|
|
|
Trace all operations. |
Off |
|
|
Trace important events, including errors, warnings, progress messages, and script processing events. |
On |
|
|
Trace SNMP script input data. |
Off |
|
|
Generate data for offline development. |
Off |
|
|
Trace SNMP script output data. |
Off |
|
|
Trace SNMP script RPCs. |
Off |
|
|
Trace the Extensible Stylesheet Language Transformations (XSLT) library. |
Off |