I have created a lab connecting 4 switches like in the topology below to test a STP with cisco sg550xg, but somehow it's creating storm and gives me this error

1y22w: %SW_MATM-4-MACFLAP_NOTIF: Host 6c3b.6b1f.7548 in vlan 200 is flapping between port Gi1/0/2 and port Fa1/0/13

enter image description here

I tried disabling the STP on the sg550xg but didn't work. I know the other 3 switches are working fine because when i skip the sg550xg and plug the cable directly from 3750 to 2950 it's working.

I noticed that the top cisco 3750 is root bridge and the cisco sg550xg is also root bridge which is strange and no port is going to blocking state.

Any suggestions will be greatly appreciated

  • You need to include the configurations in your question. ST should prevent the loop, if it doesn't the configuration must be wrong.
    – Zac67
    Dec 2, 2017 at 9:26


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