Connect to a Cluster¶
Atlas does not guarantee that host names remain consistent with respect to node types during topology changes.
If you have a cluster named
foo123 containing an analytics
foo123-shard-00-03-a1b2c.mongodb.net:27017, Atlas does
not guarantee that specific host name will continue to refer to an
analytics node after a topology change, such as
scaling a cluster to modify its
number of nodes or regions.
IP Access List¶
To access a cluster, you must connect from an IP address on the Atlas project's IP access list. If you need to add an IP address to the IP access list, you can do so in the Connect dialog. You can also add the IP address from the Network Access tab.
To access a cluster, you must create a database user with access to the desired database(s) on your Atlas cluster. Database users are separate from Atlas users. Database users have access to MongoDB databases, while Atlas users have access to the Atlas application itself.
You can create a database user to access to your Atlas cluster in the Connect dialog. You can also add the database user from the Clusters view.
Open Ports 27015 to 27017 to Access Atlas Databases¶
Make sure your application can reach your MongoDB Atlas environment. To add the inbound network access from your application environment to Atlas, do one of the following:
- Add the public IP addresses to your IP access list
- Use VPC / VNet peering to add private IP addresses.
If your firewall blocks outbound network connections, you must also open outbound access from your application environment to Atlas. You must configure your firewall to allow your applications to make outbound connections to ports 27015 to 27017 to TCP traffic on Atlas hosts. This grants your applications access to databases stored on Atlas.
By default, MongoDB Atlas clusters do not need to be able to initiate connections to your application environments. If you wish to enable Atlas clusters with LDAP authentication and authorization, you must allow network access from Atlas clusters directly to your secure LDAP . You can allow access to your LDAP by using public or private IPs as long as a public DNS hostname points to an IP that the Atlas clusters can access.
If you are not using VPC / VNet peering and plan to connect to Atlas using public IP addresses, see the following pages for additional information:
Use the Connect to your cluster Dialog to Connect to Your Cluster¶
In the Clusters view, click Connect for the cluster to which you want to connect.
Choose how you want to limit connections to your cluster.¶
Add a Connection IP Address
Skip this step if Atlas indicates in the Setup connection security step that you have already configured an IP access list entry in your cluster. To manage the IP access list, see Add Entries to the Access List.
Atlas allows standard client connections to the cluster from entries in the project's IP access list. The project IP access list differs from the API access list, which restricts API access to specific IP or CIDR addresses.
If the IP access list is empty, Atlas prompts you to add an IP address to the project's IP access list. You can either:
- Click Add Your Current IP Address to allow access from your current IP address.
- Click Add an IP Address to add a single IP address or a CIDR