Why is internet unavailable after VPN connectivity ?

Question

Let us consider I have two IP address (one assigned by VPN server and other one assign by ISP like Airtel). when user sends some data from Application then which of the layer of TCP/IP model decides that this data will be send to other end with VPN client ip or normal IP assigned by ISP ?

Answer 1

What you are looking to do is called split tunneling. If you are using a Microsoft PPTP VPN, you need to uncheck "Use default gateway on remote network" in the TCP/IPv4 (or IPv6 if using IPV6) advanced settings for the VPN connection.
If you are using another VPN client then something similar -

Step 1: goto network and sharing center and right click on your VPN and select properties.
Step 2: Goto Networking tab and select IPv4/IPv6
Step 3: Ipv6/Ipv4 window select advanced.
Step 4: In the advanced setting window goto IPsetting tab and uncheck "Use default gateway on remote network"
Step 5: Press OK>>OK>>OK

and you are done.