Stack Maintenance

x600 Series Layer 3 Gigabit Ethernet Switches Installation Guide

An operational stack configuration may require occasional maintenance when you need to add, replace or repairing a broken stack stub.

Adding a Stack Member

An unstacked switch can be added to an existing stack (hot swapped in) with minimal impact on traffic. To do this, power down the new member switch, then connect its stacking ports and power on the switch. The switch will boot as a member of the stack.

Note

The existing Stack Member-ID and the device MAC address will have no effect on the status of the new member switch. The stack will admit the new device as ordinary stack member and allocate it a new Stack Member-ID if its ID is one that already exists.

However, for good practice we recommend pre-configuring the new member with settings that are appropriate for when the new switch becomes a stack member. This is to avoid unexpected situations occurring when the stack is rebooted. For example, if the new member had a priority setting that was lower than 128 and all the existing stack members were configured with the default; then, when the stack is rebooted, the new member would be elected as the stack master.

Replacing a Stack Member

A stack member can be removed from a stack (hot swap out) with minimal impact on stack traffic. To do this power-down the stack member, disconnect its AT-StackXG ports. Insert the new stack member, reconnect the stacking ports and power-up the new stack member.

You can seamlessly swap a stack member switch into the stack to replace another with the same configuration. This provides a simple way to replace an out of service switch with minimal impact, and minimal administration requirement. You should configure the replacement switch with the same member ID as its replacement prior to its insertion into the stack.

Repairing a Broken Stub

Stack stubs can occur when a stack fault occurs and results in one of the stack members assuming the role of a stack master while the original stack master is still active. In this case, some stack members are still aware of only the original master while others are only aware of the second master. The result can be two independently operation stacks, which are termed “stubs”.

When two stub stacks are reconnected, a dual master situation is detected and the console log will display the message, ‘duplicate master' was