• SonicOS 7.1 Rules and Policies
• Overview
  • About SonicOS
  • SonicOS Workflow
  • How to Use the SonicOS Administration Guides
  • Guide Conventions
• Access Rules
  • Setting Firewall Access Rules
    • About Connection Limiting
    • Using Bandwidth Management with Access Rules
      • Enabling Bandwidth Management on an Access Rule
    • Creating Access Rules
    • Configuring Access Rules for IPv6
      • About Stateful Packet Inspection Default Access Rules
    • Enabling and Disabling Access Rules
    • Editing Access Rules
    • Deleting Access Rules
    • Restoring Access Rules to Default Settings
    • Displaying Access Rules
      • By Zones
      • By Column
    • Displaying Access Rule Traffic Statistics
    • Configuring Access Rules for NAT64
    • Configuring Access Rules for a Zone
    • Access Rules for DNS Proxy
    • User Priority for Access Rules
  • Access Rule Configuration Examples
    • Enabling Ping
    • Blocking LAN Access for Specific Services
    • Allowing WAN Primary IP Access from the LAN Zone
• NAT Rules
  • About NAT in SonicOS
  • About NAT Load Balancing
    • Determining the NAT LB Method to Use
    • Caveats
    • How Load Balancing Algorithms are Applied
    • Sticky IP Algorithm Examples
      • Example One - Mapping to a Network
      • Example Two - Mapping to an IP Address Range
  • About NAT64
    • Use of Pref64::/n
  • About FQDN-based NAT
  • About Source MAC Address Override
  • Viewing NAT Policy Entries
    • Changing the Display
    • Filtering the Display
    • Displaying Information about Policies
  • Adding or Editing NAT or NAT64 Rule Policies
  • Deleting NAT Policies
  • Creating NAT Rule Policies: Examples
    • Creating a One-to-One NAT Policy for Inbound Traffic
    • Creating a One-to-One NAT Policy for Outbound Traffic
    • Inbound Port Address Translation via One-to-One NAT Policy
    • Inbound Port Address Translation via WAN IP Address
    • Creating a Many-to-One NAT Policy
    • Creating a Many-to-Many NAT Policy
    • Creating a One-to-Many NAT Load Balancing Policy
    • Creating a NAT Load Balancing Policy for Two Web Servers
    • Creating a WAN-to-WAN Access Rule for a NAT64 Policy
    • DNS Doctoring
• Routing
  • About Routing
    • About Metrics and Administrative Distance
      • About Metrics
      • About Administrative Distance
    • Route Advertisement
    • ECMP Routing
    • Policy-based Routing
    • Policy-based TOS Routing
    • PBR Metric-based Priority
    • Policy-based Routing and IPv6
    • OSPF and RIP Advanced Routing Services
      • About Routing Services
        • Protocol Type
        • Maximum Hops
        • Split-Horizon
        • Poison Reverse
        • Routing Table Updates
        • Subnet Sizes Supported
        • Autonomous System Topologies
      • OSPF Terms
    • Drop Tunnel Interface
    • App-based Routing
  • Rules and Policies >
    • Configuring
      • Adding Static Routes
      • Probe-Enabled Policy-based Routing Configuration
• DNS Rules
  • Creating DNS Filtering Profiles
  • Configuring DNS Filtering
    • Creating DNS Policy Rules
      • Editing DNS Policies
      • Deleting DNS Policies
    • Configuring Global DNS Filtering Settings
    • Configuring DNS Filtering Custom Domains
  • Viewing DNS Information
    • Viewing DNS Using the Dashboard
    • Viewing DNS Filtering Reports
• Content Filter Rules
  • About Content Filtering Rules (CFS)
    • About Content Filter Rules
    • About UUIDs for CFS Policies
    • About Content Filter Action Objects
    • How CFS Works
  • Configuring CFS Policies
    • About the Content Filter Rule Table
      • Searching the Content Filter Rule Table
    • Adding a Content Filter Rule
    • Editing a Content Filter Rule
    • Deleting Content Filter Rules
• App Rules
  • About App Rules
    • What are App Rules?
      • About App Rules Policies
      • About App Rules Capabilities
    • Benefits of App Rules
    • How Does Application Control Work?
    • About App Rules Policy Creation
    • Licensing App Rules and App Control
    • Terminology
  • Rules and Policies > App Rules
    • Configuring an App Rules Policy
  • Verifying App Rules Configuration
    • Useful Tools
      • Wireshark
      • Hex Editor
  • App Rules Use Cases
    • Creating a Regular Expression in a Match Object
    • Policy-based Application Rules
    • Logging Application Signature-based Policies
    • Compliance Enforcement
    • Server Protection
    • Hosted Email Environments
    • Email Control
    • Web Browser Control
    • HTTP Post Control
    • Forbidden File Type Control
    • ActiveX Control
    • FTP Control
      • Blocking Outbound Proprietary Files Over FTP
      • Blocking Outbound UTF-8 / UTF-16 Encoded Files
      • Blocking FTP Commands
    • Bandwidth Management
    • Bypass DPI
    • Custom Signature
    • Reverse Shell Exploit Prevention
      • Generating the Network Activity
      • Capturing and Exporting the Payload to a Text File Using Wireshark
      • Creating a Match Object
      • Defining the Policy
• Endpoint Rules
• SonicWall Support
  • About This Document

Policy-based TOS Routing

SonicOS supports policy-based TOS (type of service) routing when defining policy-based routing (PBR) policies by Type of Service (TOS) and TOS mask values. When defined, the TOS and mask values are compared against the associated IP packet's TOS/DSCP field in the IP header when finding a route match.

The TOS value is compared to an 8-bit field in the IP packet header (for information about this header, see RFC 2474, Differentiated Services, and RFC 2168, Explicit Congestion Notification). The TOS value can be used to define services relating to quantitative performance requirements (for example, peak bandwidth) and those based on relative performance (for example, class differentiation).

TOS routing differs from existing SonicOS QoS marking, which does not affect the routing of a packet and cannot forward packets differently based on an inbound packet's TOS field. TOS Routing provides this capability by allowing policy routes to define a TOS Value/TOS Mask pair to be compared to inbound packets for differential forwarding. TOS routing only applies to packets as they enter the Security Appliance.

With TOS routing, it is possible to define multiple policy routes with identical source IP, destination IP, and service values, but differing TOS/TOS mask values. This allows packets with marked TOS fields to be forwarded differently based on the value of the TOS field in the inbound packet.

Any PBR policy routes defined before SonicOS have no values defined for the TOS/TOS mask. Likewise, the default values for TOS/TOS mask fields are zero (no values defined).

Policy routes with a TOS value other than zero are prioritized before all simple destination-only routes, but below any policy routes that define a source or service. When comparing two TOS Policy routes, and assuming both have the same set of source, destination, and service values either defined or not defined, the TOS route with the greater number of TOS mask bits set to 1 is prioritized before TOS routes with fewer TOS mask bits set.

The general prioritization (high to low) of PBR routes is as follows, based on the policy fields defined as anything other than Any or zero for TOS:

• Destination, Source, Service, TOS
• Destination, Source, Service
• Destination, Source, TOS
• Destination, Source
• Destination, Service, TOS
• Destination, Service
• Destination, TOS
• Destination
• Source, Service, TOS
• Source, Service
• Source, TOS
• Source
• Service, TOS
• Service
• TOS