Windows 7 / Networking

Understanding Rules Processing

If more than one rule matches a particular packet being examined, Windows Firewall with Advanced Security must decide which of these rules to apply to the packet so as to decide what action to take. The order in which Windows Firewall with Advanced Security processes rules is as follows:

  1. WSH rules (this is not configurable by the user)
  2. Connection security rules
  3. Authenticated bypass rules
  4. Block rules
  5. Allow rules
  6. Default rules

When a packet is being examined by Windows Firewall with Advanced Security, the packet is compared to each of these types of rules in the order they are listed. If the packet matches a particular rule, that rule is applied, and rule processing stops. In addition, if two rules in the same group match, then the rule that is more specific (that is, has more matching criteria) is the one that is applied. For example, if rule A matches traffic to 192.168.0.1 and rule B matches traffic to 192.168.0.1 TCP port 80, then traffic to port 80 on that server matches rule B, and its action is the one taken.

By default, the rule processing described previously includes both local rules (firewall and/ or connection security rules configured by the local administrator of the computer) and rules applied to the computer by Group Policy. If more than one Group Policy object (GPO) applies to a particular computer, the default rules come from the GPO with the highest precedence. Merging of local rules can be enabled or disabled using Group Policy. For more information, see the section titled "Considerations When Managing Windows Firewall Using Group Policy" later in this tutorial.

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In this tutorial:

  1. Configuring Windows Firewall and IPsec
  2. Understanding Windows Firewall with Advanced Security
  3. Improvements to Windows Firewall Introduced Previously in Windows Vista
  4. Additional Improvements to Windows Firewall in Windows 7
  5. Understanding the Windows Filtering Platform
  6. Windows Firewall and the Startup Process
  7. Understanding Windows Service Hardening
  8. Understanding Service SIDs
  9. Windows Firewall and WSH
  10. Windows Firewall and Service Triggers
  11. Understanding Multiple Active Firewall Profiles
  12. Understanding Rules
  13. Understanding Firewall Rules
  14. Inbound vs . Outbound Rules
  15. Allow vs . Block Rules
  16. Allow If Secure Rules
  17. Authenticated Bypass Rules
  18. Filtering Conditions FOR Firewall RULES
  19. Understanding Connection Security Rules
  20. Types of Connection Security Rules
  21. Supported IPsec Settings for Connection Security Rules
  22. Default IPsec Settings for Connection Security Rules
  23. Windows Firewall and Windows PE
  24. Understanding Default Rules
  25. Understanding WSH Rules
  26. Understanding Rules Processing
  27. Managing Windows Firewall with Advanced Security
  28. Tools for Managing Windows Firewall with Advanced Security
  29. Managing Windows Firewall Using Control Panel
  30. Managing Windows Firewall Using the Windows Firewall with Advanced Security Snap-in
  31. Managing Windows Firewall Using Group Policy
  32. Considerations When Managing Windows Firewall Using Group Policy
  33. Managing Windows Firewall Using the Netsh Command
  34. Common Management Tasks
  35. Enabling or Disabling Windows Firewall
  36. Configuring Firewall Profiles and IPsec Settings by Using Group Policy
  37. Creating and Configuring Firewall Rules
  38. Creating and Configuring Connection Security Rules
  39. Monitoring Windows Firewall
  40. Troubleshooting Windows Firewall
  41. Troubleshooting Windows Firewall Using Firewall Logs
  42. Troubleshooting Windows Firewall Using Event Logs
  43. Troubleshooting Windows Firewall Using Auditing
  44. Troubleshooting IPsec Issues Using Netsh Wfp
  45. Troubleshooting Windows Filtering Platform and IPsec Issues Using Netsh Trace