Example:
My intranet IP: 192.168.1.110
Subnet mask: 255.255.255.0
Gateway: 192.168.1.254
To run CMD as administrator, execute:
route add 192.168.1.0 mask 255.255.255.0 192.168.1.254 -p
Reference: http://thinkpig007.blog.51cto.com/971471/1284789