What are the two main technologies of firewalls

What are the main technologies of firewalls?

The main technologies of a firewall include:

1. Internet gateway technology:

Controls network traffic and prevents unauthorized access by connecting the network to a specific channel on the Internet.

2. Network Address Translation Technology


Hides the internal network and improves security by translating the IP address of the internal network into a public IP address.

3. Multi-level filtering technology:

Preventing unauthorized access and attacks through multi-level filtering.

4. Flexible Proxy System:

Proxy servers are used to control network traffic and prevent unauthorized access and attacks.

5. Transparent access:

Protect network security by hiding the network topology and IP address of the internal network.

6. User identification and access control:

Authenticate users by passwords, certificates, etc., and control their access to network resources.

The main technologies of firewalls include

1 Firewalls are a very effective model of network security on the Internet, by which they isolate links between risky and safe areas without preventing access to the risky areas, monitor traffic to and from the network, and allow only safe and approved information to enter, while at the same time resisting data that poses a threat to the site.

2 one of the firewall technology is a packet filtering technology, can monitor and filter the network inflow and outflow of packets, refused to send those suspicious packets, but this technology is not able to effectively distinguish between different users who agree to the IP boycott, the technology is relatively low security

3 another is the proxy service technology, mainly in the application gateway to run the application of the proxy program, on the one hand, suspicious instead of the original client Programs, on the one hand, suspicious instead of the original client to establish a connection, on the other hand, instead of the original client program to establish a connection with the server, yes, the user can safely use the network services through the application gateway, and for the Fifi user’s request is ignored.

4Another multilevel over technology, packet, application gateway, circuit gateway 3-level filtering measures, packet filtering out fake IP original address, application gateway control to monitor the general service.

Firewall technology is divided into two categories?

Divided into two categories, “packet filtering” and “application proxy” packet filtering firewalls work in the OSI network reference model of the network layer and transport layer, it is based on the packet’s header source address, destination address, port number and protocol type and other flags to determine whether or not to allow passage. Determine whether to allow the passage. Only packets that meet the filtering criteria are forwarded to the appropriate destination, and the rest of the packets are discarded from the data stream.

Application-proxy firewalls operate at the highest layer of the OSI, the application layer. It is characterized by completely “blocking” the network communication flow, through the preparation of a special proxy program for each application service, to achieve the role of monitoring and controlling the application layer communication flow.

The main function and technical support of firewall is?

Hello, the main technical support of a firewall is not encryption, the main technologies of a firewall are:

1. Internet gateway technology

2. Network Address Translation (NAT)

3. Multi-level filtering technology

4. Flexible proxy system

5. Transparent access


6. User identification and encryption

The function of the firewall is not only to prevent unauthorized information from being sent outside the network to the network, but also to filter harmful information, attack defense, anti-port scanning, IP stealth and other functions.

What are the basic techniques of firewall?

The basic techniques of a firewall are as follows:

1. Packet Filtering: The firewall decides whether to allow the packet to pass based on the information in the network packet, such as the source IP address, the destination IP address, the source port, the destination port, and the type of protocol, and compares it with a list of configured rules.

2. State detection: The firewall is able to detect the state of the network connection. For the established connection, the initial packet will be allowed to pass, while the subsequent data traffic will be examined to determine whether it meets the policy requirements.

3. Application-level gateway: This technique uses a proxy service on a specific protocol to inspect network data, such as for HTTP, FTP, SMTP, etc. It is often called a proxy server or gateway.

4. VPN: Utilizing encryption technology, a virtual private network (VPN) is established to transmit over a public network and encrypt the data to protect it from eavesdropping, tampering, or disclosure.

Combined with the above technical means, firewalls can effectively control network traffic and ensure network security.