Many users think that the function of firewall is to protect their network from attacks by illegal users. In fact, this is only one of them. Do you know the other functions of firewall? Now let's have a look!

 

five functions of firewall:

 

generally speaking, the computer firewall has the following functions:

 

1 . Allows network administrators to define a central point that prevents unauthorized users from entering the internal network.

 

2 . It can easily monitor network security and alarm.

 

3 . As the deployment location of network address translation (NAT), NAT technology can be used to alleviate the shortage of address space by dynamically or statically establishing a correspondence between the limited IP address and the internal IP address.

 

4 . It is the best place to audit and record network usage fees. Here, the network administrator can provide the management department with the cost of Internet connection, detect the potential bandwidth bottleneck location, and provide department level billing according to the organization's accounting model.

 

5 . You can connect to a separate network segment. It is physically separated from the internal network segment. The WWW server and FTP server are placed here to make them the location for disclosing internal information to the outside. Technically, it is the so-called ceasefire zone (DMZ).

 

technical comparison of two firewalls:

 

packet filtering firewall:

 

advantages: low price, low performance overhead and fast processing speed

 

disadvantages: it allows data packets with complex definitions and prone to incorrect configuration problems to pass directly, which is likely to cause potential danger of data-driven attacks

 

proxy firewall -- built in proxy application specially written to improve security, so that you can fully understand the commands of related services and ensure the security of exchanged packets. It is slow and not suitable for applications between high-speed networks (ATM or Gigabit Ethernet, etc.).