The principle and protection of DDoS attack

DDoS is a distributed Dos attack (distributed denial of service attack). Through multiple hosts to a single server attack, that is, multiple hosts constantly to the server to initiate service requests, so that the server consumes a lot of CPU, memory, network bandwidth and other resources overwhelmed, can not provide normal service or even paralysis.

DDoS protection is mainly from two aspects, that is, host settings and network settings.

Host settings:

1. Close the unnecessary service ports.

2. Limit the number of SYN half connections that are open at the same time.

3, update the system patches in time.

Network settings:

1. Deploy a firewall, prohibit internal access to specific IP addresses, prohibit access to non-open services, control the number of SYN simultaneous connections, enable DDoS properties for firewalls, and so on.

2, configure the export router, set the SYN packet traffic rate, update the iOS and so on too long.

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The principle and protection of DDoS attack