Personal Info 1 Prepared by: Mr. NHEAN Sophan  Presenter: Mr. NHEAN Sophan  Position: Desktop Support  Company: Khalibre Co,. Ltd   Tel: or  Skype: sophan.nhean  Facebook:

What Firewall can do to protect your Network? 2 Prepared by: Mr. NHEAN Sophan

Agenda 3  What is a firewall?  What does a firewall do?  What can’t a firewall do?  Who need a firewall?  How does a firewall work?  What are the protection methods of firewall?  How do we implement a firewall?  Conclusion – Benefits of firewall  Scenario  Questions and Answers Prepared by: Mr. NHEAN Sophan

What is a firewall? 4  Firewall is a component or set of computer that restrict access between a protected network and the Internet or between a sets of networks.  Protects networked computers from intentional hostile intrusion from outside.  Places a bottleneck (or Choke Point) between the networks  All communications must pass through the bottleneck – this gives us a single point of control Prepared by: Mr. NHEAN Sophan

What is a firewall? 5  There are two types of firewall Prepared by: Mr. NHEAN Sophan  Hardware firewall device Fortinet Juniper CISCO ASA  Software firewall program IP Chains & IPTables IPCop SELinux ISA

What can a firewall do? 6  A firewall examines all traffic routed between two networks to see if it meets certain criteria (allowed if it does, otherwise it dropped)  Focus on security decision (Choke point)  Enforce security policy  Log Internet Activities efficiently Prepared by: Mr. NHEAN Sophan

What can a firewall do? 7  It filters traffic base on:  Source and Destination IP address  Source and Destination Port number  Protocols used  It protect your computer and personal information from:  Hackers break into your system  Can prevent some kind of virus Prepared by: Mr. NHEAN Sophan

What can't a firewall do? 8 A firewall can’t protect you against:  Phishing scam, spyware or viruses spread through .  Malicious insider: people who gain physical access to your computer or network  For an unprotected wireless network  After network has been compromised  Connections that don’t go through firewall (Modem users)  Completely new threats Prepared by: Mr. NHEAN Sophan

Who need a firewall? 9  Anyone who is responsible for a private network that is connected to a public network.  Big, Medium, and Small Enterprise  Anyone who connect from single computer to internet via modem, etc. Prepared by: Mr. NHEAN Sophan

How does firewall work? 10  A firewall may allow all traffic through unless it meets certain criteria, or it may deny all traffic unless it meets certain criteria. Prepared by: Mr. NHEAN Sophan Outbound Inbound Basic Firewall Operation

What are the protection methods of firewall? 11  Packet Filtering  Rejects TCP/IP packets from unauthorized hosts and/or connection attempts but unauthorized hosts  Network Address Translation (NAT)  Translates the addresses of internal hosts so as to hide them from the outside world  Also known as IP masquerading  Proxy Services  Makes high level application level connections to external hosts on behalf of internal hosts to completely break the network connection between internal and external hosts Prepared by: Mr. NHEAN Sophan

How do we implement the firewall? 12  Determine the access denial methodology to use  Determine Inbound access policy  Determine Outbound access policy  Decide whether to buy a complete firewall product, have one implemented by a systems integrator or implement one yourself. Prepared by: Mr. NHEAN Sophan

Benefits of firewall 13  Protects private Local Area Network form hostile intrusion from internet  Block harmful packet to reach important resources  Allows network administrators to offer access to specific types of Internet services to selected LAN users  It can protect:  Your Data: the information you keep on computers  Your resource: the computers themselves  Your reputation: Intruders on the Internet appear with your identity. Prepared by: Mr. NHEAN Sophan

Challenging question 14 Prepared by: Mr. NHEAN Sophan Is a firewall sufficient to secure my network or do I need anything else?

Scenario 15 Firewall Scenario Prepared by: Mr. NHEAN Sophan

Scenario 1: Saturday, Midnight 16 Prepared by: Mr. NHEAN Sophan

5 Minutes later 17 Prepared by: Mr. NHEAN Sophan

Scenario 2: Monday, Midnight 18 Prepared by: Mr. NHEAN Sophan Black Hacker OK, let’s try the Insurance company…. This should take about 5 minutes!

1 minutes later 19 Prepared by: Mr. NHEAN Sophan Information Security Manager Insurance Company

5 Hours later 20 Prepared by: Mr. NHEAN Sophan Black Hacker

21 Prepared by: Mr. NHEAN Sophan Source by Building Internet Firewalls Elizabeth D. Zwicky, Simon Cooper & D. Brent Chapman