RDS Custom for Oracle

Question

Hi all,
premise: I know that it isn't a best practice, it's only for testing purpose.
I created an RDS Custom for Oracle instance, with:

Publicly accessible
Yes

and all the subnets added to the instance have in the route tables the 0.0.0.0/0 igw target.

The security group linked to RDS (and EC2 instance automatically created) has an inbound rule, port range 1521, source 0.0.0.0/0.

The listener is listening on port 1521.

The problem is that from outside (internet) is not possibile to connect directly to the db, any ideas? With telnet on public dns the port 1521 seems to be not opened.

Thanks all!

Accepted Answer

Is the subnet that you created the instance in a public one? Does the EC2 instance have an assigned public IP number? [Check http://169.254.169.254/latest/meta-data/ (IPV4) or http://[fd00:ec2::254]/latest/meta-data/ (IPV6). See: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html]. If the subnet indeed is a public subnet, and the EC2 instance does have a public IP, check Network ACL of the subnet if it prevents the traffic flow. Finally, check whether the EC2 instance has any firewall rule set up at its OS level.

If none of the above helps, then more details would be required to investigate further. This forum may not be the right place, and I suggest you open an appropriate support case with AWS Support.

All the best!

If none of the above helps, then more details would be required to investigate further. This forum may not be the right place, and I suggest you open an appropriate support case with AWS Support.

All the best!

Answer

Another try , add ssh port (22) also as inbound rule to security group and check if you can access the underlying ec2 instance. Hope the db instance is in good state and running.

Answer

I don't know what was missing yesterday, today I recreated the RDS Custom from scratch and the connection to the db from outside is ok, it seems to me I did the same things also because I noted everything.
The only difference is that today I'm working from my home and yesterday I was in my office....anyway it works, another time thanks for your help!

Answer

Yes, in the VPC I used there are 5 subnets and all public (with an igw target in the route table from 0.0.0.0/0).
Yes, EC2 has a public IP, I'm able to connect to it with the private key on port 22 (@Goki, yes, from the instance itself I'm able to connect to the DB and from the instance itself the 1521 port is open).
Check also the ACL, all the inbound and outbound traccia is allowed.
Last thing....I have to check firewall at OS level on EC2 instance, I will check and I'll let you know. Many thanks for the moment.....
I'm asking here because I'm sure it's something on my configuration, just to know if someone in the past had the same "issue". Anyway, thanks for your time and your help!

RDS Custom for Oracle

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