4th layer of the OSI model is the Transport layer. If NLB works on layer 4, then why is it called Network Load balancer and not Transport load balancer?
just about every load balancer on the market that works at layer 4 is called a "network" load balancer. It’s about marketing. network is more relatable than transport.
Don’t go with OSI layer name. It is called NLB because it is designed to work at Network level and policies defines action on ports and protocols.
Network Load Balancer is just a name, in fact it deals with TCP and UDP protocols, which belong to Transport Layer in OSI model and thus having the name "layer 4 load balancer".