Bind Two LAN Devices to non-interface IP


I have a Balance 580 v6.1.2 build 3071. My ISP has assigned me a /29 block of IP addresses. One of these is the interface IP for a WAN connection.

I have two devices on my LAN that I would like to bind to a second IP within the /29 block, not the interface IP. Is this possible?

I tried to make this happen by doing the following:

  • create a server for each device (Inbound Access–>Servers)
  • create separate TCP and UDP services for each device (Inbound Access–>Services), all of which were assigned to the desired inbound IP address
  • create outbound policies that enforce traffic from each device to the WAN interface that has the desired outbound IP address (Any destination, any port)

When these devices Google “What is my IP?”, they are listed as having the interface IP for the WAN connection I want them to use, though they are not using the IP address that I want them to use. They are still using the interface IP.

Any guidance on how to achieve having two devices use an IP other than the interface IP is appreciated.

Thanks for reading!


If you are looking to have them go outbound via the secondary IP this is done via NAT Mappings and not Outbound Policy Rules. NAT Mapping routes will by default trump the Outbound Policy rules. In the NAT Mapping rule you will just need to define the secondary (non-interface IP) as the outbound IP Address.


Thank you for the guidance. While this has helped, it has not completely solved the problem I am facing. The NAT Mappings rule that I created does allow me to specify a particular IP address on a particular WAN connection (good). What it is not letting me do is disable the Interface IPs for my other WAN connections (bad).

Is there any way to create a NAT Mappings rule that only uses one IP on one WAN interface, regardless of how many WAN interfaces I have configured or how many IPs are available across all WAN interfaces? Every time I disable the other Interface IPs, save the change, then Apply Changes, the Interface IPs are always enabled when I check the NAT Mappings rule again.

If you want these internal devices to only use the WAN with the 1-1 NAT, it would be controlled with outbound policy rules in the Balance. If you choose to use the other WANs for failover, they would get a NAT to the interface IP.