Although it is not at all recommended to assign multiple IP addresses on a computer until there are multiple network interface cards or NICs installed in it, you can still do so. The reason why it is not recommended to have multiple IP addresses on a single network adapter is to avoid the bottlenecks.
What Are Bottlenecks?
Bottleneck is when your network interface card is capable of processing a specific amount of data packets in a given time (say 100 Mbps), but receives higher amount of data packets (say 1 Gbps) which it fails to process hence degrading the overall network performance. In other words, bottleneck is a technical term for network congestion that occurs due to limited capacity of the network interface card that is responsible to forward and receive the data from other computers and nodes in the network.
If you assign multiple IP addresses to a network interface card connected to your computer, and connect the computer to a local area network, it is likely that the interface card would receive multiple data packets from the different IP addresses assigned to the computer. In such cases, the network congestion would occur, hence ending up having a bottleneck.
Practically speaking, if an organization is big enough to afford 15 to 20 computers, it is very unlikely that it would even consider of saving the funds of one NIC and would try to assign two IP addresses to one network interface card. Generally, if one computer is connected to multiple subnets because of any reason, an additional NIC is connected to the computer and configured accordingly.
However, in your case, if you are setting up a test environment and do not want to invest the funds in purchasing additional NIC, you can assign two (or more) IP addresses to a single network interface card.
Here is how you can do so:
- Log on to the computer using administrator account.
- Once logged on, press the Windows + R keys simultaneously to initiate the
Run command box.
- On the opened box, in the available field, type the NCPA.CPL command and press Enter key.
- On the opened Network Connections window, right-click the icon of the network interface card on which you want to assign multiple IP addresses.
- From the displayed context menu, go to the Properties option.
- On the opened NIC properties box, from the displayed list, double-click the Internet Protocol Version 4 (TCP/IPv4) option.
- On the opened Internet Protocol Version 4 (TCP/IPv4) Properties box, make sure that the static IP address is configured.
- Once verified, click the Advanced button.
- On the opened Advanced TCP/IP Settings box, make sure that you are on the IP Settings tab.
- Verify that the assigned IP address is displayed in the list under the IP addresses section.
- Click the Add button under the IP addresses section.
- In the opened TCP/IP Address box, provide the desired IP address and subnet mask in the IP address and Subnet mask fields respectively.
- Click OK when done.
- Back on the previous box, click OK again, and back on the Internet Protocol Version 4 (TCP/IPv4) Properties box, click OK to save the changes.
- You can now start using the computer as per the configured multiple IP addresses on a single NIC.