I cannot see the blockexplorer.com node in my peers (162.159.247.131 from
http://get-site-ip.com/)
Here are the last 15 lines of ~/.bitcoin/testnet3/debug.log
2015-05-19 22:59:02 receive version message: /Satoshi:0.9.2/: version 70002, blocks=400261, us=24.230.253.105:37037, peer=52
2015-05-19 22:59:02 Added time data, samples 53, offset -1 (+0 minutes)
2015-05-19 22:59:02 nTimeOffset = +0 (+0 minutes)
2015-05-19 22:59:02 receive version message: /Satoshi:0.10.0/: version 70002, blocks=409876, us=24.230.253.105:49047, peer=53
2015-05-19 22:59:02 Added time data, samples 54, offset +0 (+0 minutes)
2015-05-19 22:59:08 connect() to 104.200.21.137:18333 failed after select(): Connexion refused (111)
2015-05-19 22:59:09 receive version message: /Satoshi:0.10.0/: version 70002, blocks=409876, us=24.230.253.105:36463, peer=54
2015-05-19 22:59:09 Added time data, samples 55, offset +0 (+0 minutes)
2015-05-19 22:59:09 nTimeOffset = +0 (+0 minutes)
2015-05-19 23:01:35 ERROR: AcceptBlockHeader : prev block invalid
2015-05-19 23:01:35 Misbehaving: 101.81.77.219:41356 (0 -> 100) BAN THRESHOLD EXCEEDED
2015-05-19 23:01:35 ERROR: invalid header received
2015-05-19 23:01:35 ProcessMessage(headers, 162003 bytes) FAILED peer=30
2015-05-19 23:02:58 receive version message: /bitcoinseeder:0.01/: version 60000, blocks=0, us=24.230.253.105:18333, peer=55
2015-05-19 23:02:58 Added time data, samples 56, offset -1 (+0 minutes)