How to Configuring multiple gateways on a network

How to Configuring multiple gateways on a network

If you have multiple network adapters in your computer and you configure a default gateway for each

adapter (which creates a default route in the IP routing table for all destinations that are not located on

the subnet), information on your network might not be routed to the correct destinations if you connect

to disjoint networks—separate networks that are not designed to communicate directly. Only a single

gateway is used for all destinations that are not located on the subnet, even when you configure multiple

default gateways. An example of this is when a computer is connected to both an intranet with multiple

subnets and the Internet. With a default gateway configured for both adapters, you can either

communicate with all computers on the Internet or all computers on the intranet, but not both.

To solve this problem, do the following:

> Configure a default gateway for the network adapter that's connected to the network with the most
routes (usually the network adapter that's connected to the Internet).

>  Don't configure a default gateway for any other network adapter. Instead, use static routes or

dynamic routing protocols to add the routes for the other disjoint networks to the local IP routing

table. If the routing infrastructure uses Routing Information Protocol (RIP) for IPv4, you can turn

on RIP Listener in Windows, which allows your computer to learn other routes on the network by

"listening" to broadcast RIP messages, and then adding IPv4 routes to the routing table. If the

routing infrastructure doesn't use RIP, you can't use RIP listening. The alternative is to use the

route add -p command to manually add the individual routes to the IPv4 routing table. For IPv6,

you must use the netsh interface ipv6 add route command.

To configure a default gateway

1. Click to open Network Connections.

2. Right-click the network adapter that you want to configure a default gateway for, and then click

Properties. If you are prompted for an administrator password or confirmation, type the

password or provide confirmation.

3. Click the Networking tab.

4. Under This connection uses the following items, click either Internet Protocol Version 4

(TCP/IPv4) or Internet Protocol Version 6 (TCP/IPv6), and then click Properties.

5. In the dialog box that appears, select either Obtain an IP address automatically or Use the

following IP address.

The Internet Protocol Version 4

(TCP/IPv4) Properties dialog box

If you configure the network adapter to obtain an IP address automatically, the default gateway is

assigned by the DHCP server. If you specify an alternate configuration (IPv4 only), the default

gateway is the IP address in the Default gateway box on the Alternate Configuration tab. You can

only specify one default gateway.

If you manually specify an IP address configuration, the default gateway is the IP address in the

Default gateway box on the General tab.

To turn on RIP Listener

1. Click to open Programs and Features.

2. In the left pane, click Turn Windows features on or off. If you are prompted for an

administrator password or confirmation, type the password or provide confirmation.

3. Select the RIP Listener check box, and then click OK.

To manually add routes for IPv4

1. Click to open Command Prompt.

2. At the command prompt, type route -p add [destination] [mask <netmask>] [gateway] [metric<metric>] [if <interface>].