Allied Telesis x600-24Ts-POE manual VCS Failure Recovery, Fallback Action

Chapter 2: Virtual Chassis Stacking

VCS Failure Recovery

If the stack master fails or is removed, the other stack members decide which of two actions to take:

1.Fallback action.

2.Re-elect a new stack master.

Note

The master fail-over process will be slower than a stack member failure, and will require the restart (reconvergence) of routing protocols such as RIP.

Table 11, “State Change Table” on page 53 shows how the stack (non- master) members would respond to various problems occurring on the stack master stack.

Fallback Action

To initiate this action, the remaining stack members will disable all ports, then re-enable them using the fallback config file.

In order to provide an efficient alternative configuration, you should create a fallback config file that reflects the most appropriate working configuration for the failures that you feel are most likely to occur. One way to do this is to create a fall back file from your working system, then edit this file to provide an appropriate backup system configuration. See STACK FALLBACK-CONFIG command in the AlliedWare Plus Software Reference.

Re-elect New Stack Master

The stack members automatically determine which of them becomes the new VCS master.

Recombining Separated Stacks

When two separated stack units (stubs) are reconnected, a condition known as “multiple master” is detected. In this situation, a new VCS master is elected based upon the lowest Priority ID or (where both members have the same Priority ID) the lowest MAC address. The 'losing' master and the other prospective stack members will then reboot and join the new stack as ordinary stack members.

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