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Community Member

3750 stack renumbered itself


Had a system down situation yesterday. Pair of 3750s that act as the core L3 switch. All L3 services stopped. Jumped on the console, lots of messages scrolling. Messages about IP conflicts.

After a bit of poking around, I noticed that the switches had become switches 8&9 - instead of 1&2. Rebooted 1 switch, not change, powered both switches of - no change. Only fix was to renumber them back to 1&2.

Here's the actual sh switch output:

Switch# Role Mac Address Priority Version State


1 Member 0000.0000.0000 0 0 Provisioned

2 Member 0000.0000.0000 0 0 Provisioned

8 Member 001a.e28c.bb80 15 0 Ready

*9 Master 001a.e28c.d600 1 0 Ready

No-one was connected to them (as far as we are aware). Could this happen by pressing the buttons on the front? (whilst its live and running)


Community Member

Re: 3750 stack renumbered itself

Yes, it could happen if you press and hold the mode button for 10 seconds.

The stack configuration will be erased and the stack reloads. Then, the switch ID may or may not renumber depending on how the switches power up.

The config gets erased and Express Setup is initiated.


Community Member

Re: 3750 stack renumbered itself

does that clear the running config? - because it still had the config on it when i connected to it.

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