nc (netcat)でポートを指定して疎通確認

MongoDBのポート空いている？

nc -v -w 1 {IPアドレス} -z 27017

成功例

$ nc -v -w 1 localhost 80
Connection to localhost 80 port [tcp/http] succeeded!

失敗例

$ nc -v -w 1 localhost 81
nc: connect to localhost port 81 (tcp) failed: Connection refused