C7000 v2 DoS Logs

If there is an answer somewhere else, please feel free to point, laugh, and point me in the right direction.  I am getting DoS attack entries in my C7000 v2 logs.  I read in other posts on the forums that if there is an entry in the log, then the router successfully stopped it and dropped the traffic.  However, when I'm getting these entries, I'm having to power cycle my modem to get connectivity again.  This makes me think it's not being stopped.  Is there anything I can do to help stop this?  I've read about half open ports, but the gui doesn't seem to have spots for that kind of firewall customization.  I have Xfinity for an ISP.  Thanks in advance