Here is the entire passage. I'm sure your failure to include the other verses was an innocent mistake.
John 21:15 Peter the Shepherd.
When they had eaten their meal, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" "Yes, Lord," he said, "you know that I love you." At which Jesus said, "Feed my lambs."
A second time he put his question "Simon, son of John, do you love me?" "Yes, Lord," Peter said, "you know that I love you." Jesus replied, "Tend my sheep."
A third time Jesus asked him, "Simon, son of John, do you love me?" Peter was hurt because he had asked a third time...................
What he said indicated the sort of death by which Peter was to glorify God...........
Why does John keep identifying Simon as "Peter"? Why is Simon referred to as Peter or Simon Peter in Acts, The Epistles of Peter, etc? Do you have a Bible? Have you read any further than the Gospel of John?
Is John Jesus? Why should I care what any other person than Jesus calls Simon Peter?