Earlier this evening we identified one of our Cisco switch stacks misbehaving causing a constant stream of stack reconverges – this constant reconverge event has been causing layer 2 network instability for traffic flowing via the stack of nine switches.
We have just completed a physical inspection of all stack cables, including full reseating of cables as per Cisco’s guidelines – however the problem still persists.
It is possible that the stack issues are caused via a software fault within the Cisco IOS software.
We are currently applying an upgrade to the switch stack and will reboot the full stack afterwards to activate the changes.
Cisco advise doing this as a full cold reboot by removing the power from the stack members so this reload will take longer than usual.
Any customers connected to a different switch stack will only see a momentary outage during a layer 2 reconvergence.
Customers directly connected to switch stack DS-101 will see a total outage for up to 15 minutes.