Statement introduced in Junos OS Release 9.0 for EX Series switches.
Statement introduced in Junos OS Release 13.2X50-D15 for the QFX Series.
Statement introduced in Junos OS Release 13.2X51-D20 for Virtual Chassis Fabric (VCF).
Specify the roles of the members of the Virtual Chassis or a Virtual Chassis Fabric (VCF) in a preprovisioned Virtual Chassis. For a mixed Virtual Chassis or VCF, see Understanding Mixed EX Series and QFX Series Virtual Chassis or Understanding Mixed Virtual Chassis Fabric for any recommendations or requirements for assigning the Routing Engine role based on the types of switches comprising the Virtual Chassis or VCF.
Virtual Chassis Fabric
Specify the role to be performed by each switch. In a VCF, two spine devices are configured into the Routing Engine role and the remaining spine devices and all leaf devices are configured into the line-card role. The role must also be associated with the member’s serial number (see serial-number).
EX Series (except EX8200 Virtual Chassis) and QFX Series Virtual Chassis
Specify the role to be performed by each member switch. Associate the role with the member’s serial number (see serial-number).
When you use a preprovisioned configuration, you cannot modify the mastership priority or member ID of member switches through the user interfaces. The mastership priority value is generated by the software, based on the assigned role:
A member configured as routing-engine is assigned the mastership priority 129.
A member configured as line-card is assigned the mastership priority 0.
A member listed in the preprovisioned configuration without an explicitly specified role is assigned the line-card role and mastership priority 0 by default.
The configured role specifications are permanent. If both routing-engine members fail, a line-card member cannot take over as master of the Virtual Chassis configuration. You must delete the preprovisioned configuration to change the specified roles in a Virtual Chassis.
Explicitly configure two members as routing-engine and configure additional switches as members of the preprovisioned Virtual Chassis by specifying only their serial numbers. If you do not explicitly configure the role of the additional members, they function in a line-card role by default. In that case, a member that is functioning in a line-card role can take over mastership if the members functioning as master and backup (routing-engine role) both fail.
EX8200 Virtual Chassis
Specify the role to be performed by each XRE200 External Routing Engine and each EX8200 member switch. Associate the role with the member’s serial number (see serial-number). An EX8200 Virtual Chassis cannot function when both external Routing Engines, which must be configured in the routing-engine role, have failed.
line-card—Enables the member to be eligible to function only in the linecard role. Any member of the Virtual Chassis or VCF configuration other than the master or backup functions in the linecard role and runs only a subset of Junos OS for EX Series switches. A member functioning in the linecard role does not run the control protocols or the chassis management processes.
A Virtual Chassis must have at least three members for one member to function in the linecard role.
In an EX8200 Virtual Chassis configuration, all member switches must be in the linecard role.
routing-engine—Enables the member to function as a master or backup Routing Engine of the Virtual Chassis or VCF configuration. The master manages all members and runs the chassis management processes and control protocols. The backup synchronizes with the master in terms of protocol states, forwarding tables, and so forth, so that it is prepared to preserve routing information and maintain network connectivity without disruption in case the master is unavailable.
In a Virtual Chassis composed of EX Series switches (except EX8200 switches) or QFX Series switches, specify two and only two members in the routing-engine role. The software determines which of the two members assigned the routing-engine role functions as master, based on the master election algorithm. See Understanding How the Master in a Virtual Chassis Is Elected. In these Virtual Chassis, the routing-engine role is associated with a switch. For a mixed Virtual Chassis or VCF, see Understanding Mixed EX Series and QFX Series Virtual Chassis or Understanding Mixed Virtual Chassis Fabric for specific recommendations or requirements for assigning the Routing Engine role based on the types of switches comprising the Virtual Chassis or VCF. The remaining switches are configured into the linecard role.
In an EX8200 Virtual Chassis, all XRE200 External Routing Engines must be in the routing-engine role.
Required Privilege Level
system—To view this statement in the configuration.
system-control—To add this statement to the configuration.