A subinterface is a logical interface that is assigned to an existing physical interface. It’s used to break up a physical network into smaller pieces, and it allows the same IP subnet to be used on multiple interfaces.
Subinterfaces are very useful when you want to isolate traffic from one physical interface to another. For example, you might use them to segment your network into security zones or different departments.
Subinterfaces can also help you track down problems with your network. For example, if you have a problem with one of your routers and you’re having trouble tracking down the cause of the issue, using subinterfaces can help pinpoint where the problem lies.
Last modified: October 30, 2022