I have a slow internet connection - about 12Mb/s. In 10 minutes I have detected a distributed port scan on the router from different IPs. I have counted these SYN packets at in 600 seconds (10 minutes there is a total of 1119 SYN packets).
Why would this happen and what port are they looking for? ICMP packets are dropped as are all SYN packets to all ports. There is a stateful UDP filter for a few other services. What are they looking for? The ASNs come from all over the world.