debug.log extract:-
2016-10-17 02:18:43 recv version: /Satoshi:0.12.1/: version 70012, blocks=427842, relay=1, services=00000005 us=4u6qerer3ra2ag2z.onion:8333, them=127.0.0.1:50691, peer=573 2016-10-17 02:24:53 recv getheaders to end. send 5 headers (height 434643 to 434647) peer=573 2016-10-17 02:24:53 recv getheaders to 0000000000000000024ab1ddba71eee85ca86dfd0b4b34fd69403f1508ba4770. send 3 headers (height 434644 to 434646) peer=573 2016-10-17 02:24:53 recv getheaders to 00000000000000000099d92a3e8889a7c898325e91b6de75c104fe36e6a941cd. send 4 headers (height 434644 to 434647) peer=573 2016-10-17 02:24:53 historical block serving limit reached, disconnect peer=573