Connecting one device to two network (NIC) cards

Hi all
We have a device that should be connected to a motherboard with two NIC cards. We want to be able to let the device run properly by plugging it to any of the NIC cards that we have on the motherboard.
So let say for example that our external device has IP
And our motherboard has two NIC cards are as follows:
en0 IP is
en1 IP is
also en1 has as an alias also
is it possible to run the system in this situation which means;
1- When external device is connected to en0 , then it will use en0 to communicate with the device.
2- When external device is connected to en1 , then it will use the alias to connect to the device.

My concern is will that cause an IP conflict when connecting the external device to either port.
And if somebody has an idea of how to accomplish this, please reply.

Thanks for all in Advance


When you say “plugging it to” are you connecting the device directly with a cable, do you mean through a hub?

For two TCP/IP nodes to communicate on the same physical network, they need to be on the same IP network, so the following would work



These all three are on the same ‘C’ network 192.168.0

Otherwise you would need an additional device on your network, a bridge or router to connect the logical networks.

Thanks for the reply …I know that in order to communicate we need to have all devices on same network ,
but my question was if en0 and en1 can share same IP , but in one of then it is an alias to the original NIC.

but anyways we decided to go in a different direction in relation to this system

Thanks very much for the reply.