Dell 7000 Series manual Console#boot auto-copy-sw allow-downgrade

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Stacking Dell PowerConnect 7000 Series Switches

members of the stack can be powered on sequentially by powering up the switch adjacent to the last switch powered on.

A stack of units is managed and acts as a single entity when the units are connected together and are operational. If a unit cannot detect a stacking partner, the unit automatically operates as a stack of 1 with itself as the master. If a stacking partner is detected, the switch always operates in stacking mode.

When units are operating together as a stack, the following activities occur:

All units are checked for firmware version consistency on startup. By default, units with older versions of firmware are automatically upgraded with the operational firmware version on the master switch as they join the stack. If a unit has a newer software version than the master, it is not downgraded to the master’s version by default; however, the administrator can use the following command to enable this functionality:

console#boot auto-copy-sw allow-downgrade

Before adding a member that has newer version of software to a stack, the administrator should enable the automatic downgrade feature on the master switch.

Switch management and protocols such as OSPF are active only on the master, but apply to all members of the stack. Unless administratively disabled, the Nonstop Forwarding (NSF) feature periodically checkpoints the running configuration and the application state between the master and standby switches during normal stacking operation. If the master fails, the standby switch takes over operation of the stack.

Data forwarding is active on all units in the stack, including the master. Data forwarding continues to operate should the master become unavailable.

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Contents Stacking Dell PowerConnect Series Switches Dell Technical White PaperStacking Dell PowerConnect 7000 Series Switches Contents Stacking and Management IntroductionApplicability Stacking and Performance Stacking and RedundancyDual Stacking Modules Configured in a Ring Mixing M6348 and PC7000 Series Switches in a Stack Power-Up Sequencing ConsiderationsConsole#boot auto-copy-sw allow-downgrade Initial Installation and Power-up of a Stack Selecting the Master Unit Selecting the Standby UnitAutomatic Update Updating the Firmware on a StackManual Update Creating a Separate Vlan for File Downloads FTPFrom the Switching Vlan Vlan Membership page, click Add Navigate to the Routing IP IP Interface Configuration Page Stacking Dell PowerConnect 7000 Series Switches Click Apply Adding a Stack Member with Minimal Interruption Removing a Stack Member with Minimal Interruption Effect of Master Failover on PoE Devices Merging Two Operational StacksMaster Failover Scenario Stack Member FailoverFailover Scenarios Stack Split Stack Split with Manager Failure Nonstop Forwarding Initiating a Warm Failover of the Manager Unit Nonstop Forwarding ScenarioNonstop Forwarding Example NSF Scenario Configuration via CLI RouterStack Switch Switch NSF Example NSF Re-convergence Timing Parameter TimingStacking CLI Commands Small ConfigurationStacking Web Interface Summary