I am exploring NDIS Mux driver for load balancing. The use case is to balance the load at packet level. e.g. 10 packets go through say "NIC 1" and other 12 packets go through "NIC 2". I was wondering how this would work since the connection is established already through "NIC 1" and redirecting it to "NIC 2" will not work. So not sure how packet level load balancing can be handled. Am I missing a point here?
With respect, I think you have quite a bit to learn
Whether on Windows or any other platform, load balancing generally takes place at one of the OSI layers. Generally layer 2 or layer 3. Sometimes layer 7 with specialized equipment. In every case, randomly distributing packets between multiple paths is a bad choice. NDIS MUX drivers can implement layer 2 load balancing, but all of the NICs involved have to be connected to the same network (a single switch or switches that are directly connected). There are many schemes to distribute the traffic between interfaces, but in every case all of the packets for a single connection should follow a single path because there is almost no protocol that works even half as well with out of order packets as it does with in order packets
Layer 3 load balancing requires multiple connections and typically the application has to be aware of the load balancing and actively participate in it. The notable exception is HTTP 1.x where the protocol is sufficiently brain dead (one TCP connection and TLS negotiation for every request) that a load balancer can operate effectively without application support
higher level load balancing is much more complex
So if I go with distributing traffic between interfaces based on connections, is there any way in user mode to achieve that.
The simplest way is to manipulate the routing table