Loop Troubleshooting

[rossa35]

Switches: Core stack (1) SG500X-48 (1) SG500-52

Branch (1) SG350-10

I’ve never chased down a loop before, not sure where to begin, but I’ve got a rave of blinky lights happening on my switches, across server ports, and even my pfSense box is showing the flood of LAN traffic.

Do I just go cable by cable unplugging them one at a time until it stops, or is there a method to the STP madness?

Thanks in advance for your help!

/DCD

[Flavio Miranda]

Hi

 This is one possibility if this problem was not caused by any known change like port config or cabling move.

 if you lost access to the switch you can also reload them to get access back.

[marce1000]

 - You may also configure a syslog server on all (involved) Cisco switches, this sometimes makes it easier to identify the cause of a loop, 

 M.