How do I configure static IP routing for OpenVPN server on a home gateway?

A routing table is the mechanism by which a modem or router memorizes where traffic should go when received. When a router is connected to the LAN of the Comcast Gateway, that router’s routing table is dynamically added (in most cases) to the routing table of the Comcast Gateway.

This is done so that the Comcast Gateway knows where to send traffic destined for IPs which are on the separate subnet of IPs that are behind that router. By default, the Comcast Gateway’s LAN is set to assign IPs to LAN devices between 10.1.10.0 and 10.1.10.255. This is a subnet of LAN IPs. Most routers will assign IP addresses to their own LAN between 192.168.1.0 and 192.168.1.255 (a separate subnet).

In order for internet traffic to reach a device on the 192.168.1.0 subnet through the Comcast Gateway, that path must exist in the Gateway’s routing table. In some circumstances (not common), that route must be created manually. This is where static routes come in. If, for whatever reason, a router being connected between the Comcast Gateway and the rest of your LAN does not automatically update the Comcast Gateway’s routing table with its LAN information, use the Static Routing setup page on the Gateway to manually add that route.

A maximum of eight static routes may be added. To set up a static route rule, you must first know the destination IP address, the subnet mask of the destination IP address, and your LAN IP assigned to the router by the Comcast commercial gateway.

Create a static routing rule

1. Enter a Name for the router that will make the route easier to remember (has no effect on the static routing function).
2. Enter the Destination IP.
3. Enter the Subnet Mask of the destination IP.
4. Enter your local LAN Gateway IP address (The LAN IP assigned to the router connected to the Comcast commercial gateway).
5. Select Add. The new static route will be added to the static routing table.
6. Repeat steps 1 through 5 to add additional static routes.
7. Select Apply to activate the static routes.