Generator outside building grounding question

[hhsting]

Generator is located outside the building. It is separately derived system and they provide ground rods as grounding electrode conductor. However I am getting confused by NEC 2017 Article 250.30(C). My confusion is that should their be in addition to ground rods additional grounding electrode conductor going to building main service grounding electrode system or one grounding electrode conductor to ground rods is ok?

 

[Johnhall30]

It is saying that the connection to the grounding electrode shall be made at the source, which is the generator located outside. You do not need to run another grounding electrode conductor to the normal service grounding system.