在办公室的椅子上剧烈运动

Denial of service attacks are illegal means of attack. Distributed denial of service attacks make a large number of seemingly legitimate requests to service providers, consuming or occupying a large amount of resources for a long time.If an attacker sends SYN packets quickly with their own undisguised IP address, this is a so-called direct attack. This attack is very easy to implement because it does not involve spoofing or modifying packets below the user layer of the attacker's operating system. For example, he can simply send many TCP connection requests to implement this attack. However, for this attack to work, the attacker must also prevent his system from responding to SYN-ACK packets because of any ACK, RST, or ICMP (Internet? Control? Message? Protocol) will cause the server to skip the SYN-RECEIVED state (go to the next state) and remove the TCB (because the connection has been successfully established or recycled). Attackers can do this by setting firewall rules, causing the firewall to block all packets (except SYN) to reach the server, or causing the firewall to block all incoming packets so that SYN-ACK packets are discarded before reaching the local TCP handler.In other words, all the rules we customize are the rules in these four categories, or all the rules exist in these four "tables".魏铁就更放心了。怎么可能？夺命书生在不甘中，倒到地下，露出尖端沾染着鲜红的血的枪杆，眼睛大睁，死不瞑目。现在为什么突然毫不犹豫地将他们公之于众呢？听郦食其的意思，似乎尹旭有意让他知道这些人的存在。