Salesforce Authentication Failing

Question

I am trying to use OAuth authentication to get the Salesforce Authentication Token, so I referred wiki docs, but after getting authorization code, when I make a Post request

Answer 1

To whitelist an IP address range follow these steps:

1. Click Setup in the top-right
2. Select Administer > Security Controls > Network Access from the left navigation
3. Click New
4. Add your ip address range
5. Click Save