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Hierarchy Level


Disable automatic Virtual Chassis port (VCP) conversion in a Virtual Chassis.


This statement is available as of Junos OS Releases 14.1X53-D47, 17.4R2, 18.1R3, 18.2R2, and 18.3R1 only on EX Series and QFX Series switches in a Virtual Chassis that have automatic VCP conversion enabled by default, which include all EX4300, EX4600, EX4650, and QFX Series switches that support Virtual Chassis. See ../../../../virtual-chassis-ex-4200-4500/virtual-chassis-qfx/topics/concept/virtual-chassis-components.html#understanding-virtual-chassis-components__auto-vcp-conversion for details.

Configuring this statement disables the feature for the entire Virtual Chassis, and subsequently removing this statement returns the Virtual Chassis to the default behavior with automatic VCP conversion enabled.

VCP links connect members in a Virtual Chassis using supported VCP ports on the member switches. Ports that are supported as VCPs and are not dedicated VCPs or configured as VCPs by default must be converted into VCPs to use them to interconnect Virtual Chassis members. You can manually convert a supported port into a VCP port using the request virtual-chassis vc-port command, or when automatic VCP conversion is enabled, a port will be automatically converted into a VCP under the following conditions:

  • LLDP is enabled on the interfaces for the members on both sides of the link. The two interfaces exchange LLDP packets to accomplish the port conversion.

  • The Virtual Chassis must be preprovisioned with the switches on both sides of the link already configured in the members list of the Virtual Chassis using the set virtual-chassis member command.

  • The ports on both ends of the link are supported as VCPs and are not already configured as VCPs.

If you want to deterministically control VCP port conversion during a preprovisioned Virtual Chassis configuration or expansion, you might want to disable this feature and set up all VCPs manually. Otherwise, you can use the default automatic VCP conversion behavior in a “plug and play” approach to simplify adding a new switch to an existing Virtual Chassis or adding a redundant VCP link between two existing members of a Virtual Chassis.

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 Releases 14.1X53-D47, 17.4R2, 18.1R3, 18.2R2, and 18.3R1.