Amazon EC2: Security Group not respecting my custom inbound and outbound rules - amazon-ec2

so I limited my inbound and outbound in my security group policy to my ip only, however, I find that I can access it from any other IP address. does the ec2 instance need to be restarted in order to reflect the new security group policy?

No instance need not be restarted for applying security policy.
You need to check if there are multiple security-group's attached to instance.

Related

Lambda function access to EC2 instance in same security group

I am trying to access my EC2 instance configured with elasticsearch from a configured lambda function.
I've added the lambda function to the same VPC and security group as the EC2 instance. I am not sure; what's causing the issue ?
I've EC2FullAccess permissions from lambda function
The correct security configuration should be:
A security group on the Lambda function (Lambda-SG). It does not require any Inbound rules. Leave the Outbound rules as standard 'allow all'.
A security group on the EC2 instance (Elasticsearch-SG) that allows Inbound connections on the desired port (9200?) from the Lambda-SG.
That is, Elasticsearch-SG specifically allows inbound connections from Lambda-SG.
Please note that security group rules apply to each instance individually. Putting two resources 'in' the same security group does not permit access between those resources unless there is a rule that allows inbound access from itself. Thus, it is better to put different security groups on each layer of resources.
There is no need to assign EC2FullAccess permissions to the Lambda function. That is only used to call AWS to do things like launching or terminating EC2 instances.

Give EC2 access to a ELB Elastic Beanstalk system

I have a database server on a EC2 instance, I want it to accessible by Elastic Load Balancer cluster.
I tried adding the subnet of the Load Balancer security groups of database EC2.
There must be some way to give whole cluster of EC2 instance created ELB and autoscalling, access to single EC2.
Your question isn't too clear, but it appears your scenario is:
Internet -> ELB -> EC2 fleet -> Database (on EC2 instance)
You have a database running on a single EC2 instance
You have multiple EC2 instances running an application that connect to the database
You have an Elastic Load Balancer that accepts traffic from the Internet and distributes it to the EC2 instances running the application
You should configure the following Security Groups:
ELB-SG: Configure this security group to allow incoming web traffic from the Internet (0.0.0.0/0). Associate the security group to the Load Balancer.
App-SG: Configure this security group to allow incoming web traffic from ELB-SG. Associate the security group with every instance in the application fleet. If the EC2 instances are launched via Auto Scaling, then associate the security group with the Launch Configuration.
DB-SG: Configure this security group to allow incoming traffic from App-SG. Associate the security group to the EC2 instance running the database.
When I say "allow incoming traffic from xxx-SG", I mean that you should enter the name of the incoming security group in the Source field when configuring the security group. This will automatically insert the unique name of the security group (sg-xxxx). It means that any resource associated with the referenced security group will be allowed incoming access on the nominated port.
You should avoid using an IP address or CIDR range in a security group, because they can change (eg if you launch another EC2 instance). By referencing a security group by name, it will automatically update as instances are added/removed.

EC2 instances cannot ping each other

I have 2 EC2 Ubuntu instances. They are sharing same VPC, subnet and Security Group. Instances' firewall was turnoff. But I still can't ping each other by private IP. How to allow those instances ping each other?
In the security group, add "Custom ICMP" rule for "Echo Request" -- or -- "All ICMP Traffic" -- and as the source IP, instead of an address or block, add the security group's identifier, sg-xxxxxxxx.
Simply being in the same security group doesn't mean the instances can communicate among themselves. It only means they follow the same set of rules... but security group membership is a source attribute as well, on traffic originating from instances that are members of the group.
Hence, the above.
if it is windows instance, then you need to enable rule in firewall.
And also need to add inbound rule for your private CIDR range atleast

Amazon - can't connect to instance behind VPC

For testing purposes, I set up a VPC on Amazon and created an instance within the VPC. I've added a gateway for the 0.0.0.0/0 address to the attached routing table, and given the instance an elastic IP address. I'm unable to ssh or ping it, even when I set the security group to allow all traffic. I must be missing something obvious. What am I doing wrong?
It turns out that when I created the instance, I accepted the default security group, which only allows access from a specific IP address. When I added another instance, I created it with a security group which allowed all traffic, and I was able to ping it.

Access Amazon EC2 via Public IP get timeout

Currently I just create an instance on Amazon EC2 and I can ssh to the server. I installed Apache2 server and it is up but when I try to access via its public ip, then the browser come with timeout error. I have no idea related to EC2 and your idea would be worthwhile for me.
Thanks
From EC2 Docs:
If you are unable to see the Apache test page, check that the security group you are using contains a rule to allow HTTP (port 80) traffic. For information about adding an HTTP rule to your security group, see Adding Rules to a Security Group.
By default all traffics port are blocked for security reason. You need to add Inbound rules for allow http traffic(port 80)
You can add inbound rules by following these steps:
From EC2 Dashboard find "Security Groups" and then "Create Security Group"
Give a security group name and description and rules like shown in picture and then create security group.
Now you can access your ec2 public IP from anywhere.

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