When do you use BGP, IGRP, OSPF, and static route? | Networking

? BGP is used when there are number of routers in a network, such as in an Internet Service Provider (ISP) network environment
?    IGRP is used when the network is small, such as in a small company
?    OSPF is used when there are many departments in a company that need to communicate with each other
?    Static  route  is  used  for small  office or home office environment.