I. Overview
Firewalls are often used in the project, but the network gate may not be familiar with the following aspects of the network gate and firewall differences.
II. Different definitions
Figure 2.1, Example topology of a network gate
Figure 2.2, Firewall example topology
surname SanHardware Architecture
The net gates are made ofTwo hosts + one standalonehardware form, i.e., internal and external network hosts + isolation card, while the firewall uses thesingle host, therefore, the security of the gate system itself is high.
Figure 3.1, Network gate architecture
IV. Communication protocols
The firewall uses standard TCP/IP protocols; the middle channel of the network gate uses private protocols that can block the infiltration of malicious code based on standard protocols.
V. Application tiers
The netgate works onapplication layer (computing)and most firewalls work onnetwork layerThe level of control over content inspection is low; although there are agent-based firewalls that can do some content-level inspection, there is limited support for the type of application, basically only support for browsing and mail functions; at the same time, the network gate has a lot of firewalls do not have the function, and the firewalls do not have.Database, file synchronisation, custom development interfaceetc.
VI. Working modalities
Firewalls are based onrouting modework and can transmit messages directly. A netgate is a gateway on theWorking in host states, all data is converted, and the information on the intranet is completely blocked (see the example topology for details).
VII. TCP/IP sessions
All TCP/IP communication within a firewall is done between the two networks; unlike a netgate, there is no dialogue between the internal and external networks, and the connection ends at the hosts on both the external and internal networks.