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instance (Ephemeral Database)


Hierarchy Level


Enable an instance of the ephemeral configuration database.

The order in which the configuration lists the instances determines their priority when merging conflicting configuration statements from different instances into the configuration. The instances are listed in order from highest to lowest priority. In addition, user-defined instances of the ephemeral configuration database have higher priority than the default ephemeral database instance, which has higher priority than the static configuration database.


When you configure an ephemeral instance, you can specify its placement in the configuration by using the insert command instead of the set command.

Table 1 summarizes the maximum number of user-defined ephemeral database instances supported for different Junos OS variants and releases.

Table 1: Maximum Ephemeral Database Instances
Junos OS Variant and Release Maximum Instances
Junos OS Release 18.1 or earlier 8
Junos OS Release 18.2R1 or later 7
Junos OS Evolved 8


cyclic-version version

Number of versions of the ephemeral instance's database for which the system stores deleted configuration objects. After each commit, the device reclaims the space occupied by objects deleted in the previous database version relative to the current database version as determined by the cyclic version value. You can disable cyclic versioning by setting the value to 0.

Thus, starting with the 11th commit operation, the device, by default, reclaims the space occupied by objects deleted in version 1 of the database. The process continues with each subsequent commit operation.

  • Default: 10

  • Range: 0 through 4,294,967,295


User-defined name for an instance of the ephemeral configuration database.

The instance name must contain only alphanumeric characters, hyphens, and underscores, and it must not exceed 32 characters in length. In addition, starting in Junos OS Release 17.1R3, 17.2R3, 17.3R3, 17.4R2, and 18.1R1, the name of an user-defined instance cannot be default.

The remaining statements are explained separately. Search for a statement in CLI Explorer or click a linked statement in the Syntax section for details.

Required Privilege Level

maintenance—To view or add this statement in the configuration.

Release Information

Statement introduced in Junos OS Release 16.2R2 and Junos OS Evolved Release 22.1R1.

cyclic-version statement introduced in Junos OS Release 23.2R1 and Junos OS Evolved Release 23.2R1.