Can someone explain the random MAC Addresses in Syslog? Should I be concerned?

I have an AC3100 a couple of months old. Today I was checking the system log and I found multiple entries such as these

Oct 19 12:05:36 syslog: WLCEVENTD wlceventd_proc_event(500): eth1: Auth EA:06:02:EB:04:5C, status: Successful (0)
Oct 19 12:05:36 syslog: WLCEVENTD wlceventd_proc_event(529): eth1: Assoc EA:06:02:EB:04:5C, status: Successful (0)
Oct 19 12:05:46 syslog: WLCEVENTD wlceventd_proc_event(466): eth1: Deauth_ind EA:06:02:EB:04:5C, status: 0, reason: Deauthenticated because...

Can someone explain the random MAC Addresses in Syslog? Should I be concerned?