Types of Firewall
1. Packet filter:
Packet filtering inspects each packet passing through the network and accepts or rejects it based on user-defined rules.
2. Circuit-level firewall:Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.
3. Application gateway:Applies security mechanisms to specific applications, such as FTP and Telnet servers.
4. Proxy server:
Intercepts all messages entering and leaving the network acting as an intermediary between clients and servers. The proxy server hides the true network addresses