Avira security Download Mod For Android
Four types of firewalls Stateless packet filtering --- ACL Stateless packet filtering (state packet) formal packet filtering with application inspection and control Proxy server Endless packet filtering Features: (1) rely on Static policies to allow and reject packets (2) Static TCP implementation and layer 3 traffic filtering only, work very well (3) Transparent and high performance (4) Access control technology with general usage restriction Disadvantages: (1) Cannot support dynamic application (2) ) Some detection attacks cannot be resisted. State-state filtering Features: (1) Trusted Layer 3-4 (network, transmission) access control (2) Simple configuration (3) Transparency and high performance (4) General use of restricted access control technology Disadvantages: (1) lack of insight into the contents of layers 5-7 (2) If layers 3-4 movement is encoded, it cannot support dynamic Application layer monitoring and state packet filtering control Features: (1) reliable 3-7 access control layer (2) simple configuration (3) transparent and medium performance (4) restricted access control technology is generally used Disadvantages: (1) the use of Layer monitoring and performance control (2) Limited cache can be used for in-depth content analysis Proxy server Features: (1) Reliable 3-7 access control layer (2) Standardization of agreement automatically (3) Permissive or restrictive access control technology can be used Disadvantages: (1) Not all applications can be widely supported (2) Not suitable for real-time traffic to adopt this technology (3) Opaque