Stack failure recovery – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual
Page 2127
VCStack Introduction
Software Reference for x310 Series Switches
C613-50046-01 REV A
AlliedWare Plus
TM
Operating System - Version 5.4.4C
82.13
1.
If a backup member becomes the
it will first disable all its switch
ports, then activate any triggers specified with the
command that have been configured.
2.
The stack member assumes the role of stack master. In specific situations this
condition could result in a stack containing two masters. This would present problems
with network management and the control of links that were previously aggregated.
3.
The following situation will apply to a switch that has been removed from the stack by
the using the “no stack enable” command:
«
The switch will be unaware of further faults within the stack it was previously a
member of.
«
Should this switch then be powered down, all links previously shutdown (as a
result of running the no stack enable command) will remain down.
4.
If the backup member’s ports are still up, this may cause downstream switches with
trunked ports to operate incorrectly.
Stack Failure Recovery
If the stack master either fails, or is removed, the other stack members will re-elect a new
stack master. The stack members automatically determine which of them becomes the
new stack master. See the
Disabled Master Monitoring (DMM)
and the
sections for more information. Alternatively, you can manually configure a trigger with the
type stack disabled-master command on page 77.26
to activate on a stack member if it
becomes the disabled master.
shows how the stack backup members would respond to various problems
occurring on the stack master stack.
Run the no stack enable
command
3
No change
Software application failover
(lock-up or continual crashes)
No change
Re-boot as backup
member
Reboot as stack member
software crash or lock-up
No change
Frozen
4
Frozen
4
Power-down / PSU failure
No change
Powered Down
Powered down
Table 82-1: State Change Table
Note
When VCStack is used with EPSR, the EPSR failovertime must be set to at least 5
seconds to avoid any broadcast storms during failover. Broadcast storms may
occur if the switch cannot failover quickly enough before the EPSR failovertime
expires. See the
command for further information about the EPSR
failovertime.
See the
command for further information about stack failover.