Wondering how to resolve issues with an Amazon RDS database that is in an incompatible-network state? We can help you!

Here, at Bobcares, we often receive similar queries from our AWS customers as a part of our AWS Support Services.

Today, let’s see the steps followed by our Support Techs to help our customers to fix the issues with an Amazon RDS database that is in an incompatible-network state.

 

Amazon RDS database in an incompatible-network state

 
The Incompatible-network is a terminal status. Therefore, it is impossible to modify or reboot the instance when it gets into this state. But in most cases, it might still be accessible at the database level. That means we can connect to the database even though the instance is in incompatible-network state.

The incompatible-network state occurs due to the following reasons:

• The AWS subnet where the RDS DB instance is present has no enough IP addresses.
• Reaching the service quota for Elastic Network Interfaces in the AWS Region can cause incompatible-network issue.
• The subnet mentioned in the RDS DB subnet group no longer exists in the Amazon VPC.
• If the RDS DB instance is set to publicly accessible and the DNS hostnames and the DNS resolution options are disabled, the issue may occur. So make sure to enable both options for an RDS DB instance to be publicly accessible.
• The original elastic network interface of the RDS DB instance was deleted while the instance was stopped. When the RDS DB instance was restarted, the elastic network interface wasn’t found.
• While stopping the RDS DB instance, the original elastic network interface was deleted. It wasn’t found after restarting the DB instance.

The following actions can cause the incompatible-network state:

• By modifying the RDS DB instance to use a Multiple Availability Zones deployment.
• By modifying the RDS DB instance’s class.
• Replacing of the host due to any maintenance event.
• Restore from the snapshot.
• Restarting of RDS Db instance.
• Replacement of RDS DB instance.

How to fix incompatible-network state issue

 
As we already said we can’t modify or reboot the RDS DB instance in incompatible-network state. So it is always better to have a snapshot backup to be sure that we can restore the data to another RDS DB instance.

1. Log in to the AWS Management console and then open the Amazon RDS console.

2. Select Databases.

3. Select the RDS DB instance that is in incompatible-network state.

4. Then from the Connectivity & Security, note the VPC ID and subnet IDs.

5. Now open the Amazon VPC console, and then select the VPCs.

6. Select the previously noted VPC, select Actions, and then select Edit DNS hostname and Edit DNS resolution.

7. Make sure to enable DNS hostnames and DNS resolution.

8. Then elect Subnets and then make sure that all subnets noted previously are listed and have available IP addresses.

9. Now open the Amazon EC2 console, and make sure that we haven’t reached the quota for elastic network interfaces.

To resolve an RDS DB instance that is already in an incompatible-network state, and there are previously enabled automated backups for the DB instance, we need to temporarily stop any writes to the database, and then do a point-in-time recovery (PITR).

If we didn’t enable the automated backups already, we need to create a new RDS DB instance. After creating, we can migrate the data by using any backup and restore tools like mysqldump.

[Need help with more AWS queries? We’d be happy to assist]
 

Conclusion

 
To conclude, today we discussed the steps followed by our Support Engineers to help our customers to fix the issues with an Amazon RDS database that is in an incompatible-network state.