All ports are OK:
[2017-02-25 07:23:15] Starting Stratum on stratum+tcp://nnc.mypool.name:31742
[2017-02-25 07:23:15] 7 miner threads started, using 'cryptonight' algorithm.
[2017-02-25 07:23:15] Pool set diff to 1000
[2017-02-25 07:23:15] Stratum detected new block
[2017-02-25 07:23:18] accepted: 1/1 (100.00%), 127.68 H/s at diff 1000 (yay!!!)
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[2017-02-25 07:23:27] Starting Stratum on stratum+tcp://nnc.mypool.name:31744
[2017-02-25 07:23:28] 7 miner threads started, using 'cryptonight' algorithm.
[2017-02-25 07:23:28] Pool set diff to 10000
[2017-02-25 07:23:28] Stratum detected new block
[2017-02-25 07:24:42] accepted: 1/1 (100.00%), 108.61 H/s at diff 10000 (yay!!!)
---
[2017-02-25 07:24:45] Starting Stratum on stratum+tcp://nnc.mypool.name:31746
[2017-02-25 07:24:45] 7 miner threads started, using 'cryptonight' algorithm.
[2017-02-25 07:24:45] Pool set diff to 25000.1
[2017-02-25 07:24:45] Stratum detected new block
[2017-02-25 07:27:12] accepted: 1/1 (100.00%), 105.60 H/s at diff 25000 (yay!!!)