A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of the concerted efforts of a person or persons to prevent an Internet site or service from functioning efficiently or at all, temporarily or indefinitely. Perpetrators of DoS attacks typically target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root nameservers.
netstat -anp | grep "tcp\|udp" | awk {'print $5'} | cut -d: -f1 | uniq -c | sort -n
So what will be the output ?
1 0.0.0.0
1 208.80.152.2
1 208.80.152.2
1 208.80.152.3
1 209.85.135.103
1 209.85.135.113
1 74.125.43.113
2 208.80.152.2
2 208.80.152.3
2 208.80.152.3
3 0.0.0.0
3 208.80.152.2
Left column indicates the number of connection,from the IP address which shown in right column. This was taken from my local test machine. If you are under an attack,this number may vary. The number will be any number.
