Prenote: I don’t recommend opening your db to the world without any IP restrictions

W NETWORK  [thread1] Failed to connect to in(checking socket for error after poll), reason: No route to host
E QUERY    [thread1] Error: couldn't connect to server connection attempt failed :
exception: connect failed

If you really really want to open: Just start accepting traffic from mongodb default port 27017 through iptables if you are on ubuntu/debian

sudo iptables -I INPUT 6 -m state --state NEW -p tcp --dport 27017 -j ACCEPT