• 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

Creating a One-to-One NAT Policy for Outbound Traffic

One-to-one NAT for outbound traffic is another common NAT policy on a firewall for translating an internal IP address into a unique IP address. This is useful when you need specific systems, such as servers, to use a specific IP address when they initiate traffic to other destinations. Most of the time, a NAT policy such as this one-to-one NAT policy for outbound traffic is used to map a server’s private IP address to a public IP address, and it is paired with a reflexive (mirror) policy that allows any system from the public internet to access the server, along with a matching firewall access rule that permits this. The reflexive NAT policy is described in Creating a One-to-One NAT Policy for Inbound Traffic.

To create a one-to-one policy for outbound traffic

1. Navigate to the OBJECT | Match Objects > Addresses page.

   

2. Click +Add at the top of the page. The Address Object Settings dialog displays.

   

3. Enter a friendly description such as webserver_private_ip for the server’s private IP address in the Name field.
4. Select the zone assigned to the server from the Zone Assignment drop-down menu.
5. Choose Host from the Type drop-down menu.
6. Enter the server’s private IP address in the IP Address field.
7. Click Save. The new address object is added to the Address Objects table.
8. Then, repeat Step 2 through Step 7 to create another object in the Address Object Settings dialog for the server’s public IP address and select WAN from the Zone Assignment drop-down menu. Use webserver_public_ip for the Name.
9. Click Save to create the address object. The new address object is added to the Address Objects table.
10. Click Cancel to close the Address Object Settings dialog.

11. Navigate to the POLICY | Rules and Policies > NAT page.

    

12. Click +Add. The Add NAT Rule dialog displays.

13. To create a NAT policy to allow the web server to initiate traffic to the public internet using its mapped public IP address, choose the options shown in Option choices: One-to-One NAT Policy for Outbound Traffic Example:

    Option choices: One-to-One NAT Policy for Outbound Traffic Example

    Option	Value
    Original Source	webserver_private_ip
    Translated Source	webserver_public_ip
    Original Destination	Any
    Translated Destination	Original
    Original Service	Any
    Translated Service	Original
    Inbound Interface	X3
    Outbound Interface	X1
    Comment	Enter a short description
    Enable NAT Policy	Checked
    Create a reflexive policy	(dimmed when Translated Destination is Original)

14. When done, click Add to add and activate the NAT policy.

15. Click Cancel to close the Add NAT Rule dialog.

    With this policy in place, the firewall translates the server’s private IP address to the public IP address when it initiates traffic out the WAN interface (by default, the X1 interface).

    You can test the one-to-one mapping by opening up a web browser on the server and accessing the public website http://www.whatismyip.com. The website should display the public IP address you attached to the private IP address in the NAT policy you just created.