• SonicOS 7.0 Rules and Policies
• Settings
  • Configuring App/Match/Malware
  • Configuring Content Filtering Service (CFS)
    • SonicWall CFS
    • CFS Custom Category
  • Geo-IP
    • Custom List
      • Editing a Custom List Entry
      • Deleting Custom List Entries
    • Using Geo-IP Diagnostics
  • Botnet
    • Configuring Botnet Settings
    • Creating Custom Botnet Lists
    • Viewing Dynamic Botnets Lists
    • Configuring a Dynamic Botnet List Server
    • Using Botnet Diagnostics
  • Decryption (DPI-SSL)
    • Certificate
    • Common Name
    • SSL Servers
  • Decryption (DPI-SSH)
  • Signature Update
• Security Policy
  • User & Country
  • App/URL/Custom Match
• NAT Policy
  • 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
  • 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 NAT Load Balancing Policy for Two Web Servers
• 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
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        • Subnet Sizes Supported
        • Autonomous System Topologies
      • OSPF Terms
    • Drop Tunnel Interface
    • App-based Routing
  • Rules and Policies > Route Policy
    • Configuring Route Policies
      • Adding Static Routes
      • Probe-Enabled Policy-based Routing Configuration
• Decryption Policy
  • Client-side SSL Rules
  • Server-side SSL Rules
  • SSH Rules
  • Setting up the Decryption Policy Table
    • Managing the Decryption Policy Toolbars
    • Changing the Policy Priority
    • Creating Decryption Policies
      • Adding Decryption Policies
      • Editing Decryption Policies
      • Deleting Decryption Policies
• DoS Policy
  • Setting up the DoS Policy Table
    • Managing the DoS Policy Toolbars
    • Changing the DoS Policy Priority
    • Creating DoS Policies
      • Adding DoS Policies
      • Editing DoS Policies
      • Deleting DoS Policies
• DNS Policy
  • Creating DNS Policies
    • Adding DNS Policies
    • Editing DNS Policies
    • Deleting DNS Policies
  • DNS Doctoring
• Endpoint Policy
• Shadow
• 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