Can switch network device?

Question

Network administration

There are, for example, 2 connections, 1 local network, a second modem connection, for example, at the moment I am connected to a modem connection, is it possible to somehow change the network connection through ipconfig or route-add so that instead of the modem the local connection is active, and when necessary modem connection, it is without disconnecting one or another, that is, 2 are connected and change them somehow so that the IP changes in the browser?