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Hierarchy Level


Assign a primary-role priority value to a member of a Virtual Chassis or VCF. The primary-role priority is the most important factor that determines which member assumes the primary Routing Engine role in the Virtual Chassis or VCF.

A Virtual Chassis or VCF configuration has two member switches running in the Routing Engine role, one as the primary and one as the backup. The remaining members operate in the linecard role. In a preprovisioned Virtual Chassis or VCF, you configure the role for each member by associating it with the member switch’s serial number, and the Virtual Chassis assigns default primary-role priorities based on the assigned role. In a non-provisioned Virtual Chassis or VCF, you can configure roles explicitly, or the primary-role priorities of the members implicitly designate the role of each member based on the primary-role election algorithm.

The Virtual Chassis or VCF elects the member switch with the highest primary-role priority value as the primary Routing Engine. When two members have the same highest primary-role priority value among all the members, the primary-role election algorithm uses other factors to determine which of the two members functions as the primary and which is the backup. See Understanding How the Primary in a Virtual Chassis Is Elected for all the conditions considered in primary-role election.

You should assign the same (highest) primary-role priority value to the members you want to be the primary and backup Routing Engine members to ensure reliable graceful Routing Engine switchover (GRES) operation. This and other primary-role election considerations also help keep primary role from switching back and forth rapidly between the two members under failover conditions.

This statement is not used for the EX8200 Virtual Chassis, which determines primary role by external Routing Engine uptime.

A switch with a primary-role priority of 0 never takes the primary or backup role.




number—Primary-role priority value.

  • Range: 0 through 255

Required Privilege Level

system—To view this statement in the configuration.system-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 9.0.