Configuring One-to-Many NAT Load Balancing

One-to-Many NAT policies can be used to persistently load balance the translated destination using the original source IP address as the key to persistence. For example, SonicWall security appliances can load balance multiple SonicWall SSL VPN appliances, while still maintaining session persistence by always balancing clients to the correct destination SSL VPN. The following figure shows a sample topology and configuration.

Sample One-to-Many NAT Load Balancing Configuration

To configure One-to-Many NAT load balancing:
1
Go to Firewall > Access Rules and choose the policy for WAN to LAN.
2
Click on the Add… button to bring up the pop-up access policy screen.
3
When the pop-up appears, enter in the following values:
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Action: Allow
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Service: HTTPS
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Source: Any
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Destination: WAN Primary IP
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Users Allowed: All
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Schedule: Always on
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Comment: Descriptive text, such as SSLVPN LB
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Logging: Checked
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Allow Fragmented Packets: Unchecked
4
Create the following NAT policy by selecting Network > NAT Policies and clicking on the Add... button:
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Original Source: Any
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Translated Source: Original
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Original Destination: WAN Primary IP
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Translated Destination: Select Create new address object... to bring up the Add Address Object screen.
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Name: A descriptive name, such as mySSLVPN
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Zone assignment: LAN
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Type: Host
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IP Address: The IP addresses for the devices to be load balanced (in the topology shown above, this is 192.168.200.10, 192.168.200.20, and 192.168.200.30.)
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Original Service: HTTPS
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Translated Service: HTTPS
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Inbound Interface: Any
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Outbound Interface: Any
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Comment: Descriptive text, such as SSLVPN LB
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Enable NAT Policy: Checked
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Create a reflective policy: Unchecked