Networking within the organization: good or bad?

I enjoy networking for professional purposes. I like it so much that I created an online course pertaining to the subject. Based on many conversations I had with peers about this form of outreach, I know it doesn't come naturally to most. When you serve an organization, networking with your colleagues might be beneficial. But should you only focus on establishing solid contacts within the company? How about the outside world? And how much networking is too much?