Ucoin core 13 seems to often download blocks that the node has already:
just some example:
2016-01-11T06:31:40+05:30 - info: Downloaded block #47507 from peer 88.174.120.187:45001 => Already processed side block #47507-0000FC3FCF271C42FC3B7B1118D1EE618B7A7267
2016-01-11T06:31:41+05:30 - info: Downloaded block #47508 from peer 88.174.120.187:45001 => Already processed side block #47508-00001CCFF596936416DFC824BADB7AA8A95A7064
2016-01-11T06:31:41+05:30 - info: Downloaded block #47509 from peer 88.174.120.187:45001 => Already processed side block #47509-0000C17C02591D2C6F34B97F7F96DFBBF8F15946
2016-01-11T06:31:41+05:30 - info: Downloaded block #47510 from peer 88.174.120.187:45001 => Already processed side block #47510-0000217969C6F0E104A469BDC6BCD195E24B0BFD
2016-01-11T06:31:41+05:30 - warn: 404 - Not found.
{
“ucode”: 2011,
“message”: “Block not found”
}
2016-01-11T06:31:42+05:30 - debug: Remote #47510 Local #47402
2016-01-11T06:31:42+05:30 - info: Downloaded block #47402 from peer 88.174.120.187:45001 => Already processed
2016-01-11T06:31:42+05:30 - info: Downloaded block #47401 from peer 88.174.120.187:45001 => Already processed
2016-01-11T06:31:42+05:30 - info: Downloaded block #47400 from peer 88.174.120.187:45001 => Already processed
2016-01-11T06:31:43+05:30 - info: Downloaded block #47399 from peer 88.174.120.187:45001 => Already processed