Dell 7000 Series manual Adding a Stack Member with Minimal Interruption

Stacking Dell PowerConnect 7000 Series Switches

Adding a Stack Member with Minimal Interruption

When adding a new member to a stack, make sure that only the stack cables and no host-facing network cables are connected before powering up the new unit. Make sure the end-user links are not connected to any ports on the unit being added and the new member is powered off. This is important because if STP is enabled and any links are UP, then Spanning Tree Protocol (STP) re-convergence will take place as soon as the link is detected.

After the stack cables on the new member are connected to the stack, connect the switch power. Do not connect another switch to the stack until the existing members are powered up. Also, do not connect two functional, powered-up stacks together. If two functional, powered-up stacks are connected together or connect a powered-up new member to the stack, then master re-election takes place, which causes the stack that no longer has a master to reboot. See “Merging Two Operational Stacks” for more details.

An “unassigned unit” is a switch that is preconfigured to be a member of a stack, but has not been physically connected to the stack. If there are any unassigned units already configured on the stack, remove them prior to adding a new unit to stack. This is important because when there is any preconfigured unit and the master holds some configuration for that unit, as soon as the new unit is detected, the configuration is applied, which might trigger the re-convergence or startup of many other protocols. However, it is possible to intentionally pre-configure a unit. The preconfigured/unassigned units can be viewed by using the show switch CLI command shown below.

The following example shows how to view the units in the stack and remove an unassigned unit:

console#show switch

SW	Management	Standby	Preconfig	Plugged-in	Switch	Code
	Status	Status	Model ID	Model ID	Status	Version
---	---------- --------- ------------- ------------- ------------- ----------
1	Mgmt Sw		PCT7048P	PCT7028P	OK	4.0.0.6
2	Unassigned		PCT7028P		Not Present	0.0.0.0

console#configure

console(config)#stack console(config-stack)#no member 2 console(config-stack)#exit console(config)#exit

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