If a host has multiple network adapters (multiple NICs) or multiple IP addresses for each network adapter, it is called a multihomed host.
In this case, the relationship between the IP addresses (with the assigned IP names) and the host name is no longer unique.
The host name can be identical to the IP name for an IP address, or it can take on its own unique name.
If a multihomed host is addressed by another host, one of the IP names (or the corresponding IP address) must be used.
In the following graphic,
- LAN1 must use the IP name ABC to address the host ABC, whereas
- LAN2 must use the IP name XYZ to address the same host.
The name you choose by which a host is addressed, influences the route of the data traffic in the network. Application programs do not usually know the various IP names, or their accompanying LAN segments, but they do know the logical host name. Therefore, choosing the right host name is very important. If static IP routes are used, you can also access IP names and/or IP addresses that are not in your own subnet.