Is this a DDOS attack?

Question

I lost my internet connection for about 15 minutes and I checked my netgear router log and found these 3:

[DoS Attack: ACK Scan] from source: 114.77.184.189, port 44822, Tuesday, March 24,2015 19:08:15
[DoS Attack: ACK Scan] from source: 91.135.35.51, port 80, Tuesday, March 24,2015 18:53:17
[DoS Attack: ACK Scan] from source: 193.66.251.213, port 80, Tuesday, March 24,2015 18:51:31

My connection is slow and I lose internet completely from time to time, but I've never checked the logs before. Is this an attack?

Answer 1

Based on the timestamps (1min 46sec & ~15min gaps between events), this is not a DDoS. This is about par for random DoS attempts against an exposed device on the Internet, such as your Netgear router.

A DDoS would show many events flooding in at the same time... you would get lots of logged events per second, or at the very least hundreds per minute.

Answer 2

No. A DDoS attack would be generating thousands of log entries per second, not three entries over the course of 20 minutes. Like usual, your router is simply presenting minor events in the most alarming language possible to scare you into thinking it's doing something.