Using security policy of three-layer exchange to protect against network virus

At present, the threat of computer network can be divided into two kinds: one is the threat to the information in the network and the other is the threat to the equipment in the network. There are many factors affecting computer network, mainly the vulnerabilities and "backdoor" of Internet software, these vulnerabilities and flaws are the first choice of the hacker to attack.

Some hackers hacked into the interior of the network, most of which were the result of imperfect security measures. Software "Backdoor" is the software company's design programmers for their convenience and set, once the "back door" open, the consequences will be disastrous. In fact, the three-tier switch security policy also has the ability to prevent viruses. Here's a detailed description of how to use the three-tier switch's security policy to prevent viruses.

The security strategy of computer network is divided into physical security policy and access control strategy.

1. Physical Security Strategy

The purpose of physical security policy is to protect computer systems, network servers, printers and other hardware entities and communication links from natural disasters, man-made damage and line attacks, verify the identity and use of users, prevent unauthorized operation of users, and ensure that the computer system has a good electromagnetic compatibility working environment.

2. Access Control Strategy

Access control is the main strategy of network security Prevention and protection, its main task is to ensure that network resources are not illegally used and very access. It is also an important means to maintain network system security and protect network resources. Security policy is divided into Access control, network control, directory level security control, attribute security control, network server security control, network monitoring and locking control, network port and node security control. It is necessary to cooperate with each other in order to really protect the security policy, but access control is one of the most important core strategies to ensure network security.

The main source of virus intrusion is through the "backdoor" of software. Packet filter set in the network layer, first should establish a certain number of information filtering table, information filter table is based on the data received from the packet header. The information header contains the data packet source IP address, destination IP address, transmission protocol type (TCP, UDP, ICMP, etc.), protocol source port number, protocol destination port number, connection request direction, ICMP message type, etc. When a packet satisfies a rule in the filtered table, the packet is allowed to pass, otherwise it is prohibited. Such firewalls can be used to prohibit internal access by outside illegal users or to prevent access to certain service types. However, packet filtering technology can not recognize the dangerous packets, can not implement the application-level protocol processing, and can not handle UDP, RPC or dynamic protocols.

According to the anti-virus requirements of each local area network, the anti-virus control system of LAN is established, and the targeted anti-virus strategy is set up respectively.