Unable to Connect Azure to AWS RDS – Request for Technical Assistance & Meeting

Question

Unable to Connect Azure to AWS RDS – Request for Technical Assistance & Meeting

Khan, Jazeem 0

Dear Azure Support Team,

Greetings from Allianz Insurance Sri Lanka.

We are currently using Azure in conjunction with AWS for our M484 system anomaly detection solution, with both environments hosted via our FCP setup. However, we are facing an issue establishing connectivity from Azure to an AWS RDS instance.

Issue Summary:

We are unable to connect to the AWS RDS database from Azure.
Connectivity from our internal office network to the RDS instance is working as expected.
The FCP team has verified and confirmed that all required network connectivity between Azure and AWS is properly configured.
We have also implemented a Network Load Balancer in the Transitional Zone to route requests to the Enterprise Zone RDS instance.

Despite these configurations, connections from Azure to AWS RDS are failing.

Request:

We would appreciate your support in investigating and resolving this issue. Given the complexity, we believe a live discussion would be beneficial. We are available for a meeting where we can demonstrate the issue and provide additional technical details.

Please let us know your availability for a session at your earliest convenience.

Thank you for your assistance.

Khan, Jazeem 0 Reputation points

2026-06-22T06:23:30.6433333+00:00

we need your support. we can schedule a meeting
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-06-22T06:35:45.8433333+00:00
Hi @Khan, Jazeem
Thank you for reaching out. Based on the information provided, this appears to be a cross-cloud network connectivity issue between Azure and an AWS RDS instance.

Since connectivity from your internal office network to the AWS RDS instance is working and your FCP team has already verified the Azure-to-AWS network configuration, we recommend further validating the end-to-end network path from the specific Azure resource that is attempting the connection.

Could you please share the following details to help narrow down the issue?

The Azure resource type initiating the connection (VM, App Service, AKS, Databricks, etc.)

AWS RDS engine type and listening port

The exact error message or timeout observed

Results of DNS resolution and connectivity tests from Azure (for example, nslookup and Test-NetConnection)

Details of any Azure NSGs, UDRs, Azure Firewall/NVA rules, and AWS Security Groups/NACLs involved in the traffic path
Khan, Jazeem 0 Reputation points

2026-06-22T07:16:16.8733333+00:00

@Pilladi Padma Sai Manisha sure will share the details. since this is public. can we have private support. so we can share the details and screenshots
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-06-24T01:52:33.7266667+00:00

Hi @Khan, Jazeem
Apologies for delay, I have messaged in you private message you can share your details
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-07-01T01:35:58.49+00:00

Hi @Khan, Jazeem
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Khan, Jazeem 0 Reputation points

2026-07-01T05:51:44.12+00:00

Hi @Pilladi Padma Sai Manisha ,

we sent you a private message. can you please check and let us know.
Khan, Jazeem 0 Reputation points

2026-08-05T06:19:21.2433333+00:00

Hi @Pilladi Padma Sai Manisha ,

Please refer to the error below FYI,it's error code 23757, we have allowed all inbound traffic for RDS postgresql DB, Still we experience the not connecting issue.from Azure login pc we are able to access to postgre DB using pgadmin.telnets also working but azure portal unable to connect to DB.please let me know how to connect with you for a troubleshoot session in private .
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-05T08:28:45.8133333+00:00

Not that I really have the expertise that I can help, but I feel a bit confused. The post is tagged Azure SQL Database, which suggests that it is involved somewhere. But where is not really clear.

In the text you talk about connecting to RDS PostgresSQL. But in the error message it talks about connecting to MySQL. I find it difficult that the problem is due something as silly using the wrong driver. But it could help if you could clarify more exactly from what product in Azure you are trying to connect from and to what service in AWS/RDS you are trying to connect to.
Khan, Jazeem 0 Reputation points

2026-08-06T04:53:47.54+00:00

Hi @Erland Sommarskog ,

Both postgre and mysql are not working when we try to connect, above is mysql rds connection error.

we use azure web portal DB connection function to connect with aws rds mysql and postgre
Khan, Jazeem 0 Reputation points

2026-08-06T05:12:37.3266667+00:00

below is postgre error.
Khan, Jazeem 0 Reputation points

2026-08-06T05:17:00.36+00:00

same postgre connect error.
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-06T08:43:37.1566667+00:00

Hm, the error message for Postgres explicitly says Azure Database for PostgreSQL flexible server, and that is sort of correct, since you trying to connect to something else. I note the appearance of IntegrationRuntimeAWS above, but the error message makes me wonder if the portal supports connection to databases outside Azure. After all, what would the use case be for this?

Of course, if you have an application running in Azure that needs to connect to on-prem or AWS that is certainly a valid use case and I expect that to be possible. But then you should focus on that and not try to troubleshoot from the portal which may be a dead end.

I should point out that this is outside my realm of expertise (which is with SQL Server), so I may be off-target. Hopefully, Pilladi can correct if so. Then again, Pilladi may also be focused on Azure SQL Database since you tagged the question that way. That seems to be the wrong tag, but I could not find another one that would be more suitable.
Khan, Jazeem 0 Reputation points

2026-08-06T09:24:15.82+00:00

Thank you for you comments Erland and piladi, can anyone answer to this query,

Could you please clarify how the Azure web portal performs database connectivity checks? Specifically, does the connection attempt originate from Microsoft's Azure infrastructure over the public internet, or from the local network of the workstation accessing the portal?

Since this database is not permitted to be accessed from the public internet, we would like to better understand the source of the connection attempt. we use azure synapse workstation to attempt DB connection, web.azuresynapse.net.
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-06T21:52:09.66+00:00

So the screenshots you showed are from web.azuresynapse.net? Possibly, if I have the time I might go there to better understand what you are doing, but I would first need to set up a workspace.

If you are connecting from the Azure portal to somewhere, you are connecting from within Azure, certainly not from your local workstation.

1 answer

Your answer

Khan, Jazeem 0 Reputation points

2026-06-22T06:23:30.6433333+00:00

we need your support. we can schedule a meeting
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-06-22T06:35:45.8433333+00:00

Hi @Khan, Jazeem
Thank you for reaching out. Based on the information provided, this appears to be a cross-cloud network connectivity issue between Azure and an AWS RDS instance.

Since connectivity from your internal office network to the AWS RDS instance is working and your FCP team has already verified the Azure-to-AWS network configuration, we recommend further validating the end-to-end network path from the specific Azure resource that is attempting the connection.

Could you please share the following details to help narrow down the issue?

The Azure resource type initiating the connection (VM, App Service, AKS, Databricks, etc.)

AWS RDS engine type and listening port

The exact error message or timeout observed

Results of DNS resolution and connectivity tests from Azure (for example, nslookup and Test-NetConnection)

Details of any Azure NSGs, UDRs, Azure Firewall/NVA rules, and AWS Security Groups/NACLs involved in the traffic path
Khan, Jazeem 0 Reputation points

2026-06-22T07:16:16.8733333+00:00

@Pilladi Padma Sai Manisha sure will share the details. since this is public. can we have private support. so we can share the details and screenshots
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-06-24T01:52:33.7266667+00:00

Hi @Khan, Jazeem
Apologies for delay, I have messaged in you private message you can share your details
Pilladi Padma Sai Manisha 11,705 Reputation points Microsoft External Staff Moderator

2026-07-01T01:35:58.49+00:00

Hi @Khan, Jazeem
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Khan, Jazeem 0 Reputation points

2026-07-01T05:51:44.12+00:00

Hi @Pilladi Padma Sai Manisha ,

we sent you a private message. can you please check and let us know.
Khan, Jazeem 0 Reputation points

2026-08-05T06:19:21.2433333+00:00

Hi @Pilladi Padma Sai Manisha ,

Please refer to the error below FYI,it's error code 23757, we have allowed all inbound traffic for RDS postgresql DB, Still we experience the not connecting issue.from Azure login pc we are able to access to postgre DB using pgadmin.telnets also working but azure portal unable to connect to DB.please let me know how to connect with you for a troubleshoot session in private .
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-05T08:28:45.8133333+00:00

Not that I really have the expertise that I can help, but I feel a bit confused. The post is tagged Azure SQL Database, which suggests that it is involved somewhere. But where is not really clear.

In the text you talk about connecting to RDS PostgresSQL. But in the error message it talks about connecting to MySQL. I find it difficult that the problem is due something as silly using the wrong driver. But it could help if you could clarify more exactly from what product in Azure you are trying to connect from and to what service in AWS/RDS you are trying to connect to.
Khan, Jazeem 0 Reputation points

2026-08-06T04:53:47.54+00:00

Hi @Erland Sommarskog ,

Both postgre and mysql are not working when we try to connect, above is mysql rds connection error.

we use azure web portal DB connection function to connect with aws rds mysql and postgre
Khan, Jazeem 0 Reputation points

2026-08-06T05:12:37.3266667+00:00

below is postgre error.
Khan, Jazeem 0 Reputation points

2026-08-06T05:17:00.36+00:00

same postgre connect error.
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-06T08:43:37.1566667+00:00

Hm, the error message for Postgres explicitly says Azure Database for PostgreSQL flexible server, and that is sort of correct, since you trying to connect to something else. I note the appearance of IntegrationRuntimeAWS above, but the error message makes me wonder if the portal supports connection to databases outside Azure. After all, what would the use case be for this?

Of course, if you have an application running in Azure that needs to connect to on-prem or AWS that is certainly a valid use case and I expect that to be possible. But then you should focus on that and not try to troubleshoot from the portal which may be a dead end.

I should point out that this is outside my realm of expertise (which is with SQL Server), so I may be off-target. Hopefully, Pilladi can correct if so. Then again, Pilladi may also be focused on Azure SQL Database since you tagged the question that way. That seems to be the wrong tag, but I could not find another one that would be more suitable.
Khan, Jazeem 0 Reputation points

2026-08-06T09:24:15.82+00:00

Thank you for you comments Erland and piladi, can anyone answer to this query,

Could you please clarify how the Azure web portal performs database connectivity checks? Specifically, does the connection attempt originate from Microsoft's Azure infrastructure over the public internet, or from the local network of the workstation accessing the portal?

Since this database is not permitted to be accessed from the public internet, we would like to better understand the source of the connection attempt. we use azure synapse workstation to attempt DB connection, web.azuresynapse.net.
Erland Sommarskog 136.7K Reputation points MVP Volunteer Moderator

2026-08-06T21:52:09.66+00:00

So the screenshots you showed are from web.azuresynapse.net? Possibly, if I have the time I might go there to better understand what you are doing, but I would first need to set up a workspace.

If you are connecting from the Azure portal to somewhere, you are connecting from within Azure, certainly not from your local workstation.

Answer 1

Based on the described symptoms, the issue is most likely related to connectivity or configuration between Azure and the AWS RDS instance, even if basic network paths have been validated. The following checks and actions are directly supported by the documented troubleshooting guidance for connecting Azure services to AWS RDS.

Verify RDS is configured for remote connections
For Amazon RDS for SQL Server, ensure the instance accepts remote connections and that TCP/IP is enabled:
- In Amazon RDS for SQL Server Management Studio, open server → Properties → Connections and confirm Allow remote connections to this server is checked.
- In Amazon RDS for SQL Server Configuration Manager, under Amazon RDS for SQL Server Network Configuration → Protocols for MSSQLSERVER, ensure TCP/IP is enabled.
- In TCP/IP Properties → IP Addresses → IPAll, confirm the TCP Port (default is 1433) and ensure this port is used in the connection string.
- Confirm that any Windows Firewall or security group rules on the path allow inbound traffic on this port.
These steps are required for Azure services (such as Data Factory, DMS, or applications running in Azure) to connect successfully.
Validate the connection string and error codes from Azure
When connecting from Azure (for example, from an Azure service or VM), capture the exact error message and code:
- For AWS RDS SQL Server sources, common errors include:
  - Error 53 – cannot open a connection to SQL Server (network/instance not reachable).
  - Error 87 – connection string is not valid.
  - Error 18456 – login failed for user (credential issue).
- For AWS RDS MySQL, common errors include:
  - [2003] (10060) – cannot connect to MySQL server (network path/firewall).
  - [2005] – unknown MySQL server host (DNS/hostname issue).
  - [1045] – access denied for user (credentials/permissions).
  - [9002] – connection string might not be right.
Compare the error from the Azure-side client with these documented codes to narrow down whether the problem is:
- Network reachability (Error 53, 2003, 2005, 9002).
- Credentials/permissions (Error 18456, 1045, 300).
- SSL/certificate trust (server certificate not trusted).
Check SSL/TLS and certificate trust from Azure
If the connection from Azure reaches the RDS instance but fails during login with a certificate error such as “The certificate chain was issued by an authority that is not trusted”:
- Ensure the certificate used by the RDS instance is trusted by the client in Azure.
- If appropriate for the environment, enable the option to trust the server certificate in the client connection settings. This should only be done if the certificate and endpoint are trusted, and not for internet-exposed production workloads.
Confirm permissions on the RDS SQL Server instance
If the Azure-side process needs specific permissions (for example, for migration or data movement):
- Ensure the login used from Azure has the required permissions, such as VIEW SERVER STATE when using migration tools. Lack of this permission can result in errors like Error 300 – VIEW SERVER STATE permission was denied.
Use documented connectivity troubleshooting for SQL Server
For persistent connectivity failures (for example, Error 53 or 2003), follow the connectivity troubleshooting guidance:
- Review SQL Server connectivity troubleshooting to verify name resolution, port accessibility, and firewall rules.
- For AWS RDS SQL Server specifically, use the documented guidance on resolving connectivity issues and the AWS RDS connectivity troubleshooting resources.
Next steps and support engagement
If, after validating:
- RDS remote access and TCP/IP configuration,
- Correct port and connection string,
- Firewall/security group rules for the RDS port from Azure address ranges,
- SSL/certificate trust,
- And required SQL permissions,
the connection from Azure still fails while on-premises connectivity works, the next step is to:
- Collect the exact error code and message from the Azure-side client.
- Compare it against the documented error tables for AWS RDS SQL Server or MySQL.
- Engage the respective cloud support channels (Azure Support for Azure-side networking and service configuration; AWS Support for RDS-side networking and security groups) with these details.
The documentation also notes that when connectivity issues are specific to certain cloud environments and basic causes (name, service running, firewall) have been ruled out, configuration in those environments is a likely cause and should be investigated with the cloud operators.

References: