vcp-no-hold-time
Syntax
vcp-no-hold-time;
Hierarchy Level
[edit virtual-chassis]
Description
Disable the Virtual Chassis port (VCP) holddown timer for all VCPs in the Virtual Chassis or Virtual Chassis Fabric (VCF).
The VCP holddown timer is an internal mechanism that delays a Virtual Chassis reconvergence for several seconds when a VCP becomes inactive. The purpose of this delay is to provide the VCP time to return online without having to reconverge the Virtual Chassis to adjust to the inactive VCP. All traffic to the VCP is dropped while the VCP is inactive. If the VCP remains down for a time that exceeds the VCP holddown timer, a Virtual Chassis reconvergence occurs.
This statement disables the holddown timer only in an EX4300
Virtual Chassis or a mixed Virtual Chassis that contains EX4300 switches
in releases in the Junos OS 13.2X50 release train. In releases after
that, the vcp-no-hold-time option is no longer needed and
has no effect because the holddown timer is replaced by a planned
PFE restart for actions that affect Virtual Chassis reconvergence.
Switches and releases that don’t support the holddown timer
might allow you to configure this statement, but the configuration
posts a warning message saying the statement has no effect. The option
will be deprecated in an upcoming release and will no longer appear
in the CLI.
When this statement is enabled, the VCP holddown timer is disabled and the Virtual Chassis reconvergence occurs when a VCP becomes inactive. The period of time where traffic is dropped waiting for the VCP to return online is avoided.
We recommend enabling this statement after a Virtual Chassis is operational. We recommend disabling this statement when you are adding or removing member switches from your Virtual Chassis.
The VCP holddown timer cannot be viewed and is not user-configurable. You can only control whether the VCP holddown timer is enabled or disabled by configuring this statement.
In an EX4300 Virtual Chassis running a Junos OS 13.2X50
release, you should enable the vcp-no-hold-time statement
before performing a software upgrade using NSSU. If you do not enable
the vcp-no-hold-time statement, the Virtual Chassis may
split during the upgrade. A split Virtual Chassis can cause disruptions
to your network, and you may have to manually reconfigure your Virtual
Chassis after the NSSU if the split and merge feature was disabled.
For more information about a split Virtual Chassis, see Understanding Split and Merge in a Virtual Chassis.
Default
The VCP holddown timer is enabled by default on all devices that support this statement.
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 13.2X50-D10.