HP Norton Personal Firewall 2003 119

About the Internet 119

How information is transmitted over the Internet

The Internet is a packet switching network. Every communication is broken into packets by TCP (Transmission Control Protocol). Each packet contains the addresses of the sending and receiving computers along with the information to be communicated.

IP (Internet Protocol) is responsible for routing the packets to their destinations. Each packet may take a different route across the Internet, and packets may be broken up into fragments. Packets travel across the Internet, moving from one router to another. Routers look at the destination address and forward the packet to the next router. IP does not guarantee the delivery of every packet.

Router

Router

Router

Receiving computer

Router

Sending computer

Router	Router	Router

Routes that a packet or fragments of a packet may take

On the destination computer, TCP joins the packets into the complete communication. TCP may have to reorder the packets if they are received out of order, and it may have to reassemble fragmented packets. TCP requests retransmission of missing packets.

TCP/IP is often used to refer to a group of protocols used on the Internet, including UDP (User Datagram Protocol), ICMP (Internet Control Message Protocol), and IGMP (Internet Group Membership Protocol).

Contents

User’s Guide Norton™ Personal Firewall User’s Guide Copyright Notice Trademarks SYMANTEC LICENSE AND WARRANTY 1. LICENSE: YOU MAY: YOU MAY NOT: 2. CONTENT UPDATES: 5. DISCLAIMER OF DAMAGES: 6. U.S. GOVERNMENT RESTRICTED RIGHTS: 7. GENERAL: Contents Chapter Responding to emergencies About Norton Personal Firewall Installing Norton Personal Firewall Norton Personal Firewall basics Keeping current with LiveUpdate Controlling access to protected computers Guarding against intrusion attempts Protecting your privacy Chapter 9 Blocking Internet advertisements Chapter 10 Monitoring Norton Personal Firewall Appendix Troubleshooting Norton Personal Firewall About the Internet Understanding Internet risks Glossary Service and support solutions Index CD Replacement Form Responding to emergencies If you think your computer is under attack Recover from an emergency Prevent future problems Page About Norton Page Page Page Installing Norton Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Firewall basics Access Norton Personal Firewall Norton Personal Firewall Access Norton Personal Firewall from the system tray Work with Norton Personal Firewall Customize Use the Security Monitor Security Monitor Select a task with the Security Monitor Learn more with the Alert Assistant Adjust the Alerting Level Use Alert Tracker Options Internet Security Show the Alert Tracker Hide Alert Tracker Check your computer’s vulnerability to attack Security Check Security Test Security Scan for Security Risks Identify the source of communications 3Click Attacker Details 3Click View Logs Connections Intrusion Detection Stop Internet communication with Block Traffic Block Traffic Allow Traffic Customize Norton Personal Firewall About Global Settings About User Settings About Ad Blocking settings Password-protectoptions Temporarily disable Norton Personal Firewall For more information Window and dialog box Help Norton Personal Firewall Release Notes Use the User’s Guide PDF 2Click Browse CD Manual Acrobat ar500enu.exe About Norton Personal Firewall on the Web Explore online tutorials 3Click continue Subscribe to the Symantec Security Response newsletter Newsletter Subscribe Keeping current with LiveUpdate About program updates About protection updates About your subscription When you should update If you run LiveUpdate on an internal network If you can’t use LiveUpdate Obtain updates using LiveUpdate Set LiveUpdate to Interactive or Express mode Configure Interactive Mode Turn off Express mode Symantec LiveUpdate Run LiveUpdate automatically Page Page Control how people use your computer Enable file and printer sharing General Rules Modify Permit Internet access Organize computers into network zones Wizard Setup Home Networking Add Identify computers to Norton Personal Firewall Find a computer’s IP address Specify an individual computer Specify a range of computers Specify computers using a network address If you use DHCP Control how users access the Internet Control how outside users access your network If you run a Virtual Private Network Guarding against intrusion attempts How Norton Personal Firewall protects against network attacks How Norton Personal Firewall protects against network attacks Norton Personal Firewall monitors communications Intrusion Detection analyzes communications packet Visual Tracking locates attackers Customize firewall protection 3Move the slider to the Security Level that you want. Your options are: Change individual security settings To change individual security settings 3Click Custom Level 4Do one or more of the following: 2 On the Personal Firewall menu, select a level. Your options are: Customize firewall rules Enable Automatic Program Control Scan for Internet-enabledprograms Manually add a program to Program Control Change Program Control settings Manually add a firewall rule Write a firewall rule 4Select the type of connection the rule should monitor. Your options are: 6Select the computers the rule should monitor. Your options are: 8Select the protocols the rule should monitor. Your options are: 9Select the ports the rule should monitor. Your options are: 10Click Next Change an existing firewall rule Change the order of firewall rules Temporarily disable a firewall rule Remove a firewall rule Customize Intrusion Detection Signatures Exclude Include Enable or disable AutoBlock Turn on AutoBlock Unblock computers Unblock Unblock All Exclude computers from AutoBlock IP Address Restrict a blocked computer 4Click Restrict Protecting your privacy Identify private information to protect Privacy Control and SSL Add private information Private Information Edit Private Information Customize Privacy Control Change the Private Information setting Change the Cookie Blocking setting Enable or disable Browser Privacy Disable or enable secure Web connections Blocking Internet advertisements How Ad Blocking works Enable or disable Ad Blocking Enable or disable Popup Window Blocking Enable or disable Flash blocking Use the Ad Trashcan Use text strings to identify ads to block or permit How to identify Ad Blocking strings Add an Ad Blocking string Modify or remove an Ad Blocking string Page Monitoring Norton Page Page Page Page Page Page Page Troubleshooting Firewall Troubleshoot Norton Personal Firewall problems Internet service provider Problem Solution Why can’t I post information online Why did an email message I sent never arrive Why can’t I connect to the Internet via my cable modem Default Inbound NetBIOS Name How can a Web site get my browser information Page About the Internet How information is transmitted over the Internet Page How Web information is located on the Internet Requesting a page Understanding URLs How ports identify programs on servers Well-knownports How computers are identified on the Internet Page Understanding Internet risks Risks from hackers Information gathering Initial access Privilege escalation Covering tracks Risks from active content Risks from inappropriate content and activities Risks to your privacy Good cookies Bad cookies Risks from Trojan horses and viruses The likelihood of being attacked Glossary Page Page Page Page Page Page Page Service and support solutions Customer service Technical support Subscription policy Worldwide service and support Page Index Page Page Page Page Page FOR CD REPLACEMENT FORM OF PAYMENT ** (CHECK ONE): MAIL YOUR CD REPLACEMENT ORDER TO: