Cisco Catalyst 2960 Series, Configuration Manual

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to the networking device and registered with EEM. Tcl scripts are supported by EEM. As an enforced rule,
Embedded Event Manager policies are short-lived run time routines that must be interpreted and executed in
less than 20 seconds of elapsed time. If more than 20 seconds of elapsed time are required, the maxrun
parameter may be specified in the event_register statement to specify any desired value.
EEM policies use the full range of the Tcl language
’
s capabilities. However, Cisco provides enhancements to
the Tcl language in the form of Tcl command extensions that facilitate the writing of EEM policies. The main
categories of Tcl command extensions identify the detected event, the subsequent action, utility information,
counter values, and system information.
EEM allows you to write and implement your own policies using Tcl. Writing an EEM script involves:
• Selecting the event Tcl command extension that establishes the criteria used to determine when the
policy is run.
• Defining the event detector options associated with detecting the event.
• Choosing the actions to implement recovery or respond to the detected event.
EEM Policy Tcl Command Extension Categories
There are different categories of EEM policy Tcl command extensions.
The Tcl command extensions available in each of these categories for use in all EEM policies are described
in later sections in this document.
Note
Table 166: EEM Policy Tcl Command Extension Categories
Definition Category
This category is represented by the
event_register_
xxx family of event-specific commands. There is a
separate event information Tcl command extension
in this category as well:
event_reqinfo . This is the
command used in policies to query the EEM for
information about an event. There is also an EEM
event publish Tcl command extension
event_publish> that publishes an application-specific
event.
EEM event Tcl command extensions (three types:
event information, event registration, and event
publish)
These Tcl command extensions (for example,
action_syslog ) are used by policies to respond to or
recover from an event or fault. In addition to these
extensions, developers can use the Tcl language to
implement any action desired.
EEM action Tcl command extensions
These Tcl command extensions are used to retrieve,
save, set, or modify application information, counters,
or timers. EEM utility Tcl command extensions
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Information About Writing Embedded Event Manager Policies Using Tcl