DDoS attacks are a problem that most Internet industries will encounter. Especially in recent years, attack tools
https://edu.alibabacloud.com/certification/clouder_applicationsecurity?spm=a2c61.500110.200003.2.d0846ea822LuJVhave become more and more intelligent. DDoS attacks have high frequency, wide harm, and difficulty in defense. With the increasing importance of Internet companies on website security, the deployment of professional DDoS defense services has become a consensus. Generally speaking, the most effective way to deploy DDoS defense is to use DDoS high defense services.
What to do when the server is attacked by DDoS and CC? The defense strategies corresponding to these two different attack methods are also different.
If it is attacked by DDOS:
1. Ensure that the server's system files are the latest version and update the system patches in time.
2. Turn off unnecessary services.
3. Limit the number of SYN semi-connections opened at the same time.
4. Shorten the time out of SYN semi-connection.
5. Properly set up the firewall to prohibit access to non-open services of the host and restrict access to specific IP addresses.
If it is attacked by
CC attack:
The CC attack is mainly to hit the server's port and continuously access it, causing the CPU to run full and cause downtime.
Then according to the principle of CC attack:
1. Let's change the port first and block the attacked port so that the attack can be temporarily resisted.
2. IIS shields the IP. If we find the source IP of the CC attack through commands or in the log, we can set in IIS to shield the IP access to the Web site, so as to achieve the purpose of preventing IIS attacks.
Generally, cloud servers do not have defense functions or have a little very low basic defense. For example, Alibaba Cloud servers generally default to a basic defense peak of about 3-5G. If it exceeds it, it will directly black hole, and the black hole time will become more and more according to the attack frequency. Long, it has a great impact on the normal online business of the enterprise. In addition to deployment cost considerations, many companies that have already adopted cloud servers usually deploy high-defense deployments in the form of CDN forwarding, without replacing the original server resources and purchasing protection services separately.
