On login, all gems connect to the NetLDI on its listening socket, the configured port for the NetLDI. The backlog for this socket is set at 20. If there are a large number of simultaneous login requests, this backlog may be exceeded, and further logins will error with "Connection refused".
Retrying the login should succeed. Avoid initiating a large number of logins at the same time.
Last updated: 3/13/15