Every node tries to have a currentEpoch that is the highest discovered among other nodes, so this information is all the time added in ping /pong packets headers. http://Smartermarkets.co/__media__/js/netsoltrademark.php?d=Products-dd.com%2Fcategory%2F%25e0%25b8%25aa%25e0%25b8%25a1%25e0%25b8%25b2%25e0%25b8%25a3%25e0%25b9%258c%25e0%25b8%2597%25e0%25b8%2597%25e0%25b8%25b5%25e0%25b8%25a7%25e0%25b8%25b5%2F