I have 3 new Cisco 2960x switches that i am adding to existing stacks. Two of the three stacks went fine, however the third stack is giving me an issue.
When plugging in the new switch, and attempting any sort of network traffic on the stack, i get huge packet loss across the network. If i unplug the new switch, the packet loss goes away.
I added the new switch by first matching the firmware of the existing stack, and then plugging in the stacking cables and booting it up, allowing the existing stack to auto provision the new switch.
In the stack config everything shows up as OK, however now with the switch off it is running at half speed. When plugging in the stack, i removed stacking cable from switch 1 to switch 3 and moved it to go to switch 4. Then i added the new stack cable from switch 3 and switch 4.
I first thought it might be a spanning-tree issue, but there hasn't been topology changes over 24 hours, so it doesn't correlate to the packet loss. I also don't understand why it is affecting all the other switch stacks in the building and the core switches/firewalls.
Any ideas? Could it be a bad stacking cable or port?
Thanks in advance!
