You can configure NAT rules in case you have multiple Internet routable IP addresses and you want to use specific ones based on special conditions. For example, you may want outgoing SMTP traffic to use a specific IP address. This feature is commonly used in combination with port forwarding to configure 1 to 1 NAT for an internal system.
Note: Before configuring NAT rules make sure you assign IP aliases to your designated WAN interface and test that you can ping them from remote networks.
Adding / Editing NAT Rules
- Go to Settings > Firewall > NAT to configure NAT Rules.
- Click Create New Rule or edit an existing rule by clicking the edit icon next to the item.
- Give the rule a description.
- Set conditions for your rule. See Rules Overview for conditions syntax and rule execution.
- Set an action of New Source and enter the IP alias you want to use based on the condition.
- Click Create Rule.
- Click Save to confirm the new rule.