My IP blacklisted?
From one host
root@vz45447:~# telnet stratum.nicehash.com 3336
Trying 159.8.2.66...
Connected to stratum.nicehash.com.
Escape character is '^]'.
^]
telnet> quit
Connection closed.

from other
root@bamt-miner:~# telnet stratum.nicehash.com 3336
Trying 159.8.2.66...
telnet: Unable to connect to remote host: Connection refused

banned host 213.87.122.0 , but can moved over 213.87.0.0/16 network.