DOS and Port Scans

[#1]

Should I be concerned about the following  DOS and PORT SCANS reported by my modem/router?
Could someone enlighten me on what they mean?  Thanks.

Tue, 2019-10-22 07:00:01 - Send E-mail Success!
Tue, 2019-10-22 11:06:00 - Send out NTP request to 212.159.6.10
Tue, 2019-10-22 11:06:03 - Receive NTP Reply from 212.159.6.10
Tue, 2019-10-22 13:28:38 - TCP Packet - Source:91.123.157.56,54886 Destination:31.185.206.54,3130 - [DOS]
Tue, 2019-10-22 13:28:39 - TCP Packet - Source:91.123.157.56,54889 Destination:31.185.206.54,3129 - [DOS]
Tue, 2019-10-22 13:28:39 - TCP Packet - Source:91.123.157.56,54893 Destination:31.185.206.54,808 - [DOS]
Tue, 2019-10-22 13:28:39 - TCP Packet - Source:91.123.157.56,54897 Destination:31.185.206.54,80 - [DOS]
Tue, 2019-10-22 13:28:39 - TCP Packet - Source:91.123.157.56 Destination:31.185.206.54 - [PORT SCAN]
Tue, 2019-10-22 13:28:39 - Send E-mail Success!
Tue, 2019-10-22 13:28:41 - TCP Packet - Source:91.123.157.56,54884 Destination:31.185.206.54,8000 - [DOS]
Tue, 2019-10-22 13:28:41 - TCP Packet - Source:91.123.157.56,54866 Destination:31.185.206.54,9999 - [DOS]
Tue, 2019-10-22 13:28:41 - TCP Packet - Source:91.123.157.56,54878 Destination:31.185.206.54,8090 - [DOS]
Tue, 2019-10-22 13:28:41 - TCP Packet - Source:91.123.157.56,54872 Destination:31.185.206.54,8888 - [DOS]
Tue, 2019-10-22 13:28:41 - TCP Packet - Source:91.123.157.56 Destination:31.185.206.54 - [PORT SCAN]
Tue, 2019-10-22 16:33:18 - TCP Packet - Source:91.123.157.56,56141 Destination:31.185.206.54,8888 - [DOS]
Tue, 2019-10-22 16:33:20 - TCP Packet - Source:91.123.157.56,56143 Destination:31.185.206.54,9090 - [DOS]
Tue, 2019-10-22 16:33:20 - TCP Packet - Source:91.123.157.56,56146 Destination:31.185.206.54,53281 - [DOS]
Tue, 2019-10-22 16:33:20 - TCP Packet - Source:91.123.157.56,56164 Destination:31.185.206.54,9999 - [DOS]
Tue, 2019-10-22 16:33:20 - TCP Packet - Source:91.123.157.56 Destination:31.185.206.54 - [PORT SCAN]
Tue, 2019-10-22 16:33:20 - Send E-mail Success!
Tue, 2019-10-22 16:33:21 - TCP Packet - Source:91.123.157.56,56143 Destination:31.185.206.54,9090 - [DOS]
Tue, 2019-10-22 16:33:21 - TCP Packet - Source:91.123.157.56,56129 Destination:31.185.206.54,3130 - [DOS]
Tue, 2019-10-22 16:33:21 - TCP Packet - Source:91.123.157.56,56136 Destination:31.185.206.54,8000 - [DOS]
Tue, 2019-10-22 16:33:21 - TCP Packet - Source:91.123.157.56,56125 Destination:31.185.206.54,81 - [DOS]
Tue, 2019-10-22 16:33:27 - TCP Packet - Source:91.123.157.56,56164 Destination:31.185.206.54,9999 - [DOS]
Tue, 2019-10-22 16:33:27 - TCP Packet - Source:91.123.157.56,56135 Destination:31.185.206.54,8081 - [DOS]
Tue, 2019-10-22 16:33:27 - TCP Packet - Source:91.123.157.56,56128 Destination:31.185.206.54,3128 - [DOS]
Tue, 2019-10-22 16:33:27 - TCP Packet - Source:91.123.157.56,56139 Destination:31.185.206.54,8118 - [DOS]
Tue, 2019-10-22 16:33:27 - TCP Packet - Source:91.123.157.56 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:07:27 - TCP Packet - Source:80.82.77.231 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:07:28 - Send E-mail Success!
Wed, 2019-10-23 00:08:27 - TCP Packet - Source:89.248.162.172 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:08:34 - TCP Packet - Source:80.82.77.221 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:09:25 - TCP Packet - Source:80.82.77.231 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:10:34 - TCP Packet - Source:80.82.77.132 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:10:35 - TCP Packet - Source:80.82.77.231 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:10:35 - Send E-mail Success!
Wed, 2019-10-23 00:10:35 - TCP Packet - Source:80.82.77.132 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:10:36 - TCP Packet - Source:80.82.77.231 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:11:35 - TCP Packet - Source:89.248.162.172 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 00:11:36 - TCP Packet - Source:80.82.77.221 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 01:45:14 - TCP Packet - Source:23.228.101.195 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 01:46:14 - UDP Packet - Source:23.228.101.195 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 01:46:55 - TCP Packet - Source:179.43.143.146 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 01:47:02 - UDP Packet - Source:179.43.143.146 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 02:18:03 - UDP Packet - Source:62.210.172.131,5132 Destination:31.185.206.54,5073 - [DOS]
Wed, 2019-10-23 02:18:06 - UDP Packet - Source:62.210.172.131,5132 Destination:31.185.206.54,5076 - [DOS]
Wed, 2019-10-23 02:18:06 - UDP Packet - Source:62.210.172.131,5132 Destination:31.185.206.54,5074 - [DOS]
Wed, 2019-10-23 02:18:06 - UDP Packet - Source:62.210.172.131 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 02:18:06 - Send E-mail Success!
Wed, 2019-10-23 03:55:09 - UDP Packet - Source:217.61.61.187,5110 Destination:31.185.206.54,5075 - [DOS]
Wed, 2019-10-23 03:55:13 - UDP Packet - Source:217.61.61.187 Destination:31.185.206.54 - [PORT SCAN]
Wed, 2019-10-23 03:55:13 - Send E-mail Success!
Wed, 2019-10-23 06:07:08 - TCP Packet - Source:45.227.255.202,65532 Destination:31.185.206.54,4037 - [DOS]
Wed, 2019-10-23 06:07:10 - TCP Packet - Source:45.227.255.202,65532 Destination:31.185.206.54,4047 - [DOS]
Wed, 2019-10-23 06:07:10 - TCP Packet - Source:45.227.255.202,65532 Destination:31.185.206.54,4033 - [DOS]
Wed, 2019-10-23 06:07:10 - TCP Packet - Source:45.227.255.202,65532 Destination:31.185.206.54,4043 - [DOS]
Wed, 2019-10-23 06:07:10 - TCP Packet - Source:45.227.255.202,65532 Destination:31.185.206.54,4039 - [DOS]
Wed, 2019-10-23 06:07:10 - Send E-mail Success!

[#2]

This is quite normal - just people poking your router half-heartedly to see if it has open ports in weak effort to break through your firewall.

[#3]

Thanks for the assurance. Judging by the time (1 month) it took to get a reply from the forum and the absence of "I have the same problem" posts it seems I am the only one who worried about nothing.

[#4]

Port scanning has been a security issue for a while now, and the internet community seems happy to live with it. Several of the IP addresses on your list have also scanned my ports on several occasions. If you put the IP address into   https://www.ipinfolookup.com/    You can see where the address is located in the world and how many others have reported problems with that IP address. Most seem to be in places like China, Estonia and Russia. I'm surprised that there is no route to report these addresses to Plusnet so that they can block those IP addresses from their end. Luckily, most routers block the access, but all of these unsolicited port scans every day have the potential to slow down the internet for all, but nobody currently cares it seems!

[#5]

The amount of traffic is trivial and many of these IP addresses are dynamically allocated, so the geographical address is going to change periodically meaning that you are trying to cause trouble for mostly the wrong person.