Hmm when a server awaits for incoming connections, it listens on a port. But in other net libraries I used one would always specifiy an IP(the local IP usually), or "localhost" (127.0.0.1) along with a port to bind on.
I have not found where we specify such a thing with SFML...
In Python one would do this:
import socket
HOST = socket.gethostbyname(socket.gethostname()) #that should return 192.168.1.1xx
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
edit: oh well... for some unknown reason, restarting my computer made it possible for me to connect to a sf::SocketTCP other than from localhost