The article highlights a significant change in Junos OS that users may observe after upgrading from Junos OS version 20.4 or earlier to Junos OS 21.1 or later, in the form of the application identification database version of 999 (default sigpack).

Prior to Junos OS Release 21.1

root@srx> show service application-identification version
  Application package version: 0

Junos OS Release 21.1 and Later

root@srx> show services application-identification version
 Application package version: 999
 Release date: Thu Feb 11 14:42:27 2021 UTC

This is expected behavior because there is application identification signature incompatibility between Junos OS Release 21.1 and later and Junos OS Release 20.4 and earlier.

To address this, you must update the application identification database by using the command "request services application-identification download" followed by "request services application-identification install".

Example

user@host> request services application-identifications download             
Please use command "request services application-identification download status"
to check status

user@host> request services application-identifications download status             
Application package 1608 is downloaded successfully.

user@host> request services application-identification install             
Please use command "request services application-identification install status" to check status and use command "request services application-identification proto-bundle-status" to check protocol bundle status

user@host> request services application-identification install status             
Install application package version (1776) succeed.

2023-07-17: Initial version