Firewall And VPN

A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predefined rules.
Think of it as a security guard standing at the network’s entrance, deciding which traffic to allow and which to block.

Types of Firewalls

1. Packet-Filtering Firewall
   • Works at the network layer.
   • Examines source/destination IP, ports, protocol.
   • Simple but limited (doesn’t inspect payload).
2. Stateful Inspection Firewall
   • Tracks active connections (the “state” of traffic).
   • More secure than packet-filtering.
3. Proxy Firewall (Application Layer)
   • Intercepts traffic between user and service.
   • Can inspect traffic at application level (e.g., HTTP, FTP).
4. Next-Generation Firewall (NGFW)
   • Combines firewall + IDS/IPS + application awareness + threat intelligence.
   • Can block malware, filter content, and detect suspicious behavior.

Examples: Palo Alto, Fortinet FortiGate, Cisco Firepower.

Which Firewall is the Best?

There’s no single “best” — it depends on needs:

• Palo Alto Networks → Excellent NGFW, strong threat detection, great for enterprises.
• Fortinet FortiGate → Very popular, cost-effective, strong security features, great performance.
• Cisco Firepower/ASA → Reliable, widely used, integrates with Cisco networking gear.
• Sophos/Checkpoint → Good for mid-size organizations, solid endpoint integration.

 VPN (Virtual Private Network)

A VPN creates an encrypted tunnel between a user/device and the network, so traffic is private and secure even across the internet.

Why VPNs are Used

• Secure remote access to corporate resources.
• Protect data confidentiality and integrity.
• Hide IP addresses and prevent eavesdropping.

VPN Types

1. Remote Access VPN – for individual users connecting remotely (common for employees).
2. Site-to-Site VPN – for connecting entire networks securely over the internet (e.g., branch offices).

Cisco provides VPN solutions through Cisco AnyConnect Secure Mobility Client and Cisco routers/firewalls.

Cisco VPN

• Cisco AnyConnect:
  • Used by end-users to securely connect to corporate networks.
  • Encrypts traffic using SSL or IPsec.
  • Supports MFA (multi-factor authentication).
• Cisco Site-to-Site VPNs:
  • Configured on Cisco routers/ASA firewalls.
  • Commonly use IPsec tunnels to link branch offices to HQ.