I would like to know what are the protocols used to connect enterprise network with the ISP ?

[matildarani1]

Is BGP the only option or we can use static routing ,ospf with redistribution ?

I am aware BGP is an exterior gateway protocol and it can be used to connect two different AS ,But my question is to know if IGP protocols or static routing can be used to connect enterprise network with the ISP .

Also specifically about static routing ?Can it be used to for neighbor-ship and communicate with ISP ?

[balaji.bandi]

Its all depends on ISP provider.  Do you have your Own AS number to peer with ISP ? If not then you have Limited Options.

Some provider do OSPF / Eigrp  (but you need to check with ISP provider)

If no AS number, ISP do not support IGP, The only Option you have is static Route.

[matildarani1]

Thank you very much for the update .We have an AS number ,so i am guessing
a BGP ,OSPF ,EIGRP will work .

Thanks again

[balaji.bandi]

If you have own AS Number BGP is prefer Method, So you have Control If you like to Peer with Another ISP Later.