why access switch has flapping lead another distribution layer switch has root guard blocking and unblocking log

[martlee2]

is it misconfiguration in Access Point's access switch or hacker attack from this switch?

many MATM-4-MACFLAP_NOTIF Host 0015.5dc1XXX VLAN 1 is flapping between port 1 and port 2

many MATM-4-MACFLAP_NOTIF Host 0015.5dc2XXX VLAN 1 is flapping between port 1 and port 2

many MATM-4-MACFLAP_NOTIF Host 0015.5dc3XXX VLAN 50 is flapping between port 1 and port 2

many MATM-4-MACFLAP_NOTIF Host 0015.5dc4XXX VLAN 50 is flapping between port 1 and port 2

last time we do not have these switch also meet the same issue about distribution layer switch have many ports down

last time someone mention a switch lost config, but today, i remember that the switch has reloaded and can be login again with radius, 

today i do not connect any notebook with this switch and just have configured radius setting for window NPS radius server and then reload, then

i have dinner and come back and after a while, last time's issue happen again. 

it seems port channel easy to have problem when abnormal traffic coming from access switch  result in down port in distribution layer switch

i wonder whether someone can hack through the switchport access mode port and send some broadcast message

[petenixon]

From that output and your description it looks like you have an STP issue as a result of misconfiguration somewhere.

Are your access points connected to switches with ports in access mode or trunk mode?