Hi,

Can anyone let me know how to add 2 ips in one NIC and its uses and advantage.

What exactly are you trying to do? One NIC can only connect to one network at a time.

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Originally Posted by ScottGem

What exactly are you trying to do? One NIC can only connect to one network at a time.

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Well... yes and no. There is a caveate. You can only do this if manual address assignments are made. It CAN NOT be performed through DHCP.

It can have only one physical connection but there can be multiple logical connections. If the networks are physically connected to each other, then assigning two or more addresses to the same nic would be of benefit. If a physical pathway exists between the two networks (ie. Switch to switch) then the single NIC connection can logically communicate to each of the networks. There are other examples of why you would do this but I will stick to just this one...

Network A - 172.16.0.0 Subnet Mask 255.255.0.0 Gateway 172.16.1.1
Network B - 192.168.1.0 Subnet Mask 255.255.255.0 Gateway 192.168.1.1

You want to communicate with both networks.

Go to your TCP/IP configuration for your network card and disable DHCP and assign an available address outside of your DHCP Scope. You will need to fill in the subnet mask, gateway address and DNS server addresses for your PRIMARY network connection. Then go to the Advanced options and add a second IP address with the correct Subnet Mask. DO NOT add a second gateway address or try and add a second set of DNS servers, etc.

To be able to route through both networks, you will need to add a static route for the secondary network address. In the example above, you would go to a CMD prompt and type the following for a persistent route:

ROUTE ADD -P 192.168.1.0 MASK 255.255.255.0 192.168.1.1

Now type ROUTE PRINT and hit enter. You should see your primary network address routes with the 172.16.0.0 addresses with one of the entries being your NIC address. Then below, you should see the static route that you added. This is the EXCEPTION to the primary routes.

Since you are sharing the same NIC for multiple networks, the bandwidth will also be shared.

OK... one more example. If you have an Internal web server and you want to have multiple web sites for different purposes and each has a unique name, one way to accomplish this (outside of using Host Headers) is to assign multiple IP addresses to the same NIC.

Example:
192.168.1.15 - server
192.168.1.16 - FTP site
192.168.1.17 - Help Desk
192.168.1.18 - portal

One is assigned to an FTP site with its own IP address. One is assigned to a Help Desk web site with its own IP address. Another is assigned to a company Portal... you got it... with its own IP address.

Then in DNS, assign friendly names for each of the IP addresses. You can then access each of the web sites or FTP site via their unique names even though they are all located on the same physical server; and it has... yep... its own unique IP address.

Then you move the web site... no problem. Delete the IP address and reassign it elswhere... done.

Thank u dear this was an helpful topic