How to share 2 Internet connections (1 main + 1 failover) to one network?

Question

Is it possible to share 2 Internet connections with a single network on Windows 10 via Internet Connection Sharing (ICS)? I'm able to share my primary Internet connection via ICS, however I'd like to be able to connect my phone's hotspot and have it as a failover option for when my main Internet goes down.

To do this I'm going to use a wireless to ethernet bridge vs connecting directly to the wireless on the system since it seems more reliable.

NOTE: I'm not interested in bonding the Internet connections (I'd have to use something like Speedify for that).

Up to now I've been trying to use Connectify, but it has some bug where it cuts Internet speeds by about 1/6 and I ended up having to use ICS to share the connection.

Answer 1

"Internet Connection Sharing" allows your computer to take a single internet connection, us it itself, AND via another network port share that connection with other computers. The computer acts like a router and DHCP server when this is enabled. What you are looking for is typically called "network load balancing".

Hardware load balancers will have less effect on the throughput of the total network connection than software load balancers, especially software running on your computer.

Load Balancing routes individual connections over one connection or the other, and if there is a failure on one of the uplinks, it fails over the connections to the working uplink. Because of this the maximum speed possible over a load balancer is only the maximum speed of one of the currently active connections by itself.

To summarize: Internet Connection Sharing is NOT for sharing two internet connection. Load Balancing is what allows you to use multiple discrete internet uplinks for a single network. And software load balancing is ALWAYS going to have a substantial performance penalty.