Configure NAT

Now NAT needs to be configured to translate traffic destined to the modem to the new interface. This is necessary so the modem sees the traffic sourced from an IP on its local subnet. Without this NAT, it would be necessary to configure a route on the modem so it knows how to reach the internal subnet. With some modems this isn’t possible, and in most cases it’s easier to NAT the traffic so routing isn’t a concern. To add the NAT, browse to Firewall > NAT, and click the Outbound tab. Switch to Manual Outbound NAT and click Save. A rule for LAN to WAN is automatically added.

Click +  to add a new Outbound NAT rule. For Interface, specify ModemAccess. For Source, specify Network, with the LAN subnet entered. The Destination is the IP subnet of the modem. In the Translation box, select Interface Address.

Then click Save and Apply changes.

It should now be possible to access the modem from LAN.