You are currently troubleshooting a network issue with your isp's customer support agent. the agent requests that you open a command prompt and type "ping 127.0.0.1". what does this accomplish?
Proves you ISP's rep is an idiot. ping localhost just sends an ICMP (Internet Control Messaging Protocol) echo request packet through a logical (not physical) interface. In effect, if it succeeds, your machine can talk to itself.