we've following situation
- switch A is third party unmanaged switch
- switch B is Catalyst 2950 or 2960
- switch C is Catalyst 2950 acting as "Service Provider Egde"
Switch A is connected to access port of switch B (configured with portfast), switches B and C are connected using 802.1q trunk
Someone created loop betweeen two interfaces of switch A. Switch B didn't have any suspicious message in the log, switch C shows "%SW_MATM-4-MACFLAP_NOTIF: Host XXXX.XXXX.XXXX in vlan YYY is flapping between port Gi0/3 and port Gi0/24".
Is there any feature, which can help us detect and mitigate such problem on switch B?
Thanks. Jan Klicka, SITMP