Allied Telesis x600-48Ts, x600-24Ts/XP, x600-24Ts-POE VCStack Recovery States, Ring Configuration

Chapter 2: Virtual Chassis Stacking

Ring Configuration

A virtual stack using x600 switches can comprise up to 4 stack members connected in a ring topology. Figure 25 shows a ring comprising 3 stacked x600 series switches. Because an alternate path is provided between the stack members, this topology offers a very resilient configuration

100-240VAC~
RPS INPUT	AT-StackXG				High Speed Stacking Cables
		STACK PORT 1	STACK PORT 2
					Model Number AT-StackXG/0.5
					(0.5 meters) as supplied or
					Model Number AT-StackXG/1
		High Speed Stacking Cables			(1.0 meter)
		Model Number AT-StackXG/0.5
			(0.5 metres)
100-240VAC~
	RPS INPUT	AT-StackXG
			STACK PORT 1	STACK PORT 2
			High Speed Stacking Cables
			Model Number AT-StackXG/0.5
				(0.5 metres)
100-240VAC~
		RPS INPUT	AT-StackXG
				STACK PORT 1	STACK PORT 2

Figure 25. VCS Ring Topology Using x600 Switches

Resiliency Link Stack Resiliency Link

VCStack Recovery States

The purpose of the resiliency link is to provide the stack members with status information that enables them to detect whether the stack master is still operational after it has suffered either a power-down or software lock- up. This enables the other stack members to either operate in the fall-back mode, or to re-elect a new stack master. The state change table,Table 10, “State Change Table” on page 55 shows how the stack members respond to various problems occurring on the master node.

A resiliency link operates using a resiliency link VLAN to which resiliency link switch ports can become members.

The following state-change-table shows stack member failure conditions and recovery actions in situations where the resiliency link is present or absent.

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