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An Introduction to Firewall Technology Agenda What is a firewall Why an organization needs a firewall Types of firewalls and technologies Deploying a firewall What is a VPN What is a Firewall ? A firewall : Acts as a security gateway between two networks Usually between trusted and untrusted networks (such as between a corporate network and the Internet) What is a Firewall ? A firewall : Acts as a security gateway between two networks Tracks and controls network communications Decides whether to pass, reject, encrypt, or log communications (Access Control) Why Firewalls are Needed Prevent attacks from untrusted networks Protect data integrity of critical information Preserve customer and partner confidence Evolution of Firewalls Packet Filter Packets examined at the network layer Useful “first line” of defense - commonly deployed on routers Simple accept or reject decision model No awareness of higher protocol layers Application Gateway or Proxy Packets examined at the application layer Application/Content filtering possible - prevent FTP “put” commands, for example Modest performance Scalability limited Stateful Inspection Packets Inspected between data link layer and network layer in the OS kernel State tables are created to maintain connection context Invented by Check Point Network Address Translation (NAT) Converts a network’s illegal IP addresses to legal or public IP addresses Hides the true addresses of individual hosts, protecting them from attack Allows more devices to be connected to the network Port Address Translation—Hiding Personal Firewalls Need arises from always on connections Your PC is not protected enough by your OS Intrusion detection facilities Different levels of security Templates Firewall Deployment Corporate Network Gateway Protect internal network from attack Most common deployment point Firewall Deployment Corporate Network Gateway Internal Segment Gateway Protect sensitive segments (Finance, HR, Product Development) Provide second l