Mongodb error connection



I have 2 raspberry pi 3 on the same local network, with mongodb + mongoexpress + nodered, installed in the same way on each one.
the first one is for, the second is, when I make requests from the first to the second using the node mongodb2 of the kind, mongodb: // 27017 / db it works perfectly, by cons on the second to the first when I try a request on mongodb: // 27017 / db, I have a message like: MongoError: failed to connect to server [] on first connect [MongoError: connect ECONNREFUSED].
I prescribe that the two databases work perfectly.
I do not understand where the problem comes from.
have you an idea about this?
see you


Hello, i find a way by myself, the trouble is in the setup of mongodb in, you must change in
etc/mongodb.conf the value bind_ip change to and also port:27017.
see you