A new asset field type for which the first part is a simple text field, and the second part allows tagging an asset. (Or, allow to mix and match any 2 compatible parts)
For example, you could then create a header for "Interfaces", then have 2 part fields where you type the name of the interface, and tag/link an assigned IP address asset.
It is currently possible to create enough custom assets to essentially accomplish the same goal, but this could drastically cut down on the number of assets needed to put together this sort of information.
The reason that the existing "link asset" field won't work for this is because interface names will be drastically different between devices. So, you would have to create a custom asset type for each individual model, or work around it as I am doing by breaking network interfaces out to be their own custom assets, and linking them from network devices assets.
There may be an entirely different and better method to accomplish this. This is just one idea.