A Distributed Denial of Service (DDoS) attack overwhelms your server with excessive traffic, causing it to become unavailable for genuine users. If your Linux server experiences high load, slow performance, or downtime, it could be a sign of a DDoS attack.<\/p>\r\n
Steps to check if your Linux server is under a DDoS attack:<\/p>\r\n
netstat -n | grep :80 | wc -l<\/pre>\r\nThis command will display the number of active connections. If the number is unusually high, it may indicate an attack.<\/li>\r\n
\u00a0netstat -an | grep SYN<\/pre>\r\nIf the result shows a large number of SYN connections (typically above 100), your server might be experiencing a SYN flood attack.<\/li>\r\n
netstat -anp | grep 'tcp\\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n<\/pre>\r\nThis will display a list of IP addresses with the number of connections they are making to your server. If you notice an IP address with an unusually high number of connections, it may be the source of the attack.<\/li>\r\nroute add <IP address> reject<\/pre>\r\n<\/li>\r\n
route add 192.168.0.1 reject<\/pre>\r\n<\/li>\r\n
route -n | grep <IP address><\/pre>\r\n<\/li>\r\n
iptables -A INPUT -s <IP address> -j DROP
service iptables restart
service iptables save<\/pre>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n
killall -KILL httpd
service httpd start<\/pre>\r\n<\/li>\r\n
In this way, you can check\u00a0whether your\u00a0Linux Server<\/a> is under a DDoS attack<\/span>.<\/p>\r\n Also, check our Cloud Services Today!<\/p>\r\n","protected":false},"excerpt":{"rendered":" A Distributed Denial of Service (DDoS) attack overwhelms your server with excessive traffic, causing it to become unavailable for genuine users. If your Linux server experiences high load, slow performance,…<\/p>\n