[2][3][4] One advantage of using split tunneling is that it alleviates bottlenecks and conserves bandwidth as Internet traffic does not have to pass through the VPN server.
A disadvantage is that when split tunneling is enabled, users bypass gateway level security that might be in place within the company infrastructure.
[5] For example, if web or content filtering is in place, this is something usually controlled at a gateway level, not the client PC.
ISPs that implement DNS hijacking break name resolution of private addresses with a split tunnel.
By default all datagrams enter the tunnel except those destination IPs explicitly allowed by VPN gateway.