using a periodic configuration or by initiating an on-demand CLI. The regular download update happens only
when the version of the requested DS is different from the version of the DS on the device. Periodic download
is only started after there is any DS assigned to the device from DS web portal. After the assignment happens,
the response to the periodic inventory message from the same device will include a field to notify device to
start its periodic DS download/update. In a DS update request message, the status and revision number of the
DS is included such that only a DS with the latest revision number is downloaded.
Forced-download downloads a specific DS or a set of DSes. You can trigger the forced-download update
request only by initiating an on-demand CLI. In a force-download update request, the latest version of the DS
file is downloaded irrespective of the current DS file version on the device.
The DS file is digitally signed, and signature verification is performed on every downloaded DS file to make
sure it is from a trusted source.
Diagnostic Signature Workflow
The diagnostic signature feature is enabled by default in Cisco software. The following is the workflow for
using diagnostic signatures:
1
Find the DS(es) you want to download and assign them to the device. This step is mandatory for regular
periodic download, but not required for forced download.
2
The device downloads all assigned DS(es) or a specific DS by regular periodic download or by on-demand
forced download.
3
The device verifies the digital signature of every single DS. If verification passes, the device stores the
DS file into a non-removable disk, such as bootflash or hard disk, so that DS files can be read after the
device is reloaded. On the Cisco CSR 1000v, the DS file is stored in the bootflash:/call home directory.
4
The device continues sending periodic regular DS download requests to get the latest revision of DS and
replace the older one in device.
5
The device monitors the event and executes the actions defined in the DS when the event happens.
Diagnostic Signature Events and Actions
The events and actions sections are the key areas used in diagnostic signatures. The event section defines all
event attributes that are used for event detection. The action section lists all actions which should be performed
after the event happens, such as collecting s
how
command outputs and sending them to Smart Call Home to
parse.
Diagnostic Signature Event Detection
Event detection in a DS is defined in two ways: single event detection and multiple event detection.
Diagnostic Signature Actions
The diagnostic signature (DS) file consists of various actions that must be initiated when an event occurs. The
action type indicates the kind of action that will be initiated in response to a certain event.
Variables are elements within a DS that are used to customize the files.
DS actions are categorized into the following four types:
•
call-home
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Configuring Call Home for the Cisco CSR 1000v
Information About Diagnostic Signatures
