Access AWS Network Load Balancer from VPC - amazon-web-services

I have a VPC with current subnets:
public-subnet has access to Internet Gateway:
routing public:
172.31.0.0/16 -> local
0.0.0.0/0 -> igw
private-subnet has NAT Gateway:
routing private:
172.31.0.0/16 -> local
0.0.0.0/0 -> nat
internal-subnet have access to Internet Gateway:
routing internal:
172.31.0.0/16 -> local
0.0.0.0/0 -> nat
My Lambda function is deployed in a private subnet. In internal-subnet deployed network balancer and ecs task. I want to make requests from my lambda in private-subnet to network load balancer.
I tried different approaches but always get timeouts. I tried to make request bu private task IP but still getting timeouts.
How to configure access from one subnet to load balancer in another subnet inside VPC?

Related

Send AWS load balancer traffic to data interface of instances

I am using AWS classic load balancer to distribute traffic to instances present in a auto scale group.
Each instance has 3 interfaces (1 management, 2 data interface).
I want my loadbalancer to send traffic to data interface 1, but I have found any way to do this. Loadbalancer is sending traffic to management interface only.
Subnet CIDR:
Management: 10.0.1.0/24 -> Public
Data1: 10.0.2.0/24 -> Private
Data2: 10.0.3.0/24 -> Private
Load balancer is present in public subnet, and instances are getting created in private subnet.
Route table
Public:Management subnet is associated, and internet gateway is attached.
Private: Data1 and Data2 subnet is associated and nat gateway is attached.

Is there a way to assign one static elastic IP to multiple instances?

Is there anyway that many ec2 instances can share the same IP? So that all outbound API requests from the ec2 instances, are coming from the same IP address? If the API provider were to whitelist the single static IP address, it would grant access to all of the instances.
Any ideas would be great!
If this is for outbound only, then it can be achieved using a NAT Gateway.
All the EC2 instances will sit behind the public NAT Gateway, the NAT Gateway is then assigned an Elastic IP Address.
All traffic from the EC2 instances will be routed via the NAT Gateway to the Internet Gateway and the target environment will see all the traffic originating from the Elastic Ip Address assigned to the NAT Gateway.
However, if traffic must go the other way (inbound), then this architecture will not work.
UPDATE: The NAT Gateway must reside in a public subnet, that subnet will have a route 0.0.0.0/0 to the Internet Gateway. The EC2 instances will reside in a private subnet and have a route 0.0.0.0/0 to the NAT Gateway in the public subnet.
Furthermore for High Availability it is recommended that you have at least 4 subnets, 2 in 2 different Availability Zones (AZ). A NAT Gateway does not span subnets and so at least two NAT Gateways should be used one in public subnet A which resides in the first AZ and the other in public subnet B which resides in the second AZ.
The architecture would be as follows:
Where Routing Table A (Associated with both public subnets) has a route to the Internet Gateway i.e.
10.0.0.0/16 - local
0.0.0.0/0 - igw-xxxxxxxxx
Routing Table B is associated with private subnet 10.0.10.0/24 has a route to the NAT Gateway in the public subnet (10.0.0.0/24) i.e.
10.0.0.0/16 - local
0.0.0.0/0 - nat-123456
Routing Table C is associated with private subnet 10.0.11.0/24 has a route to the NAT Gateway in the public subnet (10.0.1.0/24) i.e.
10.0.0.0/16 local
0.0.0.0/0 nat-654321
In this architecture each NAT Gateway will have it's own Elastic IP address which means 2 IP Addresses will be visible to the target, if high availability is not important then you could use 1 NAT Gateway in one public subnet. Note that, a NAT gateway supports 5 Gbps of bandwidth and automatically scales up to 45 Gbps. If you require more bandwidth, you can split your resources into multiple subnets and create a NAT gateway in each subnet.
For more detailed information on configuring a NAT within a VPC see the following page in the docs.

AWS Fargate Cluster unable to access Internet with NAT and Internet Gateways in place

I'm trying to deploy containers to a private network Fargate cluster on AWS. I do have an Internet Gateway on my single VPC:
And I do have a NAT Gateway for that particular subnet in the very same VPC where my cluster/services live:
Routing seems OK for that Subnet as well:
And the security group for the service do not block any incoming connection:
But my containers don't even start with the infamous exception: CannotPullContainerError: Error response from daemon:Get https://registry-name/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers) Why? Thanks.
You don't have the subnet configured to use the NAT gateway. Your routing table currently sends traffic directly to the IGW, which makes the subnet a public subnet, not a private subnet, which means anything in that subnet would need to have a public IP assigned to it. NAT Gateways existing in the same subnet as other resources don't magically give those resources Internet access, you have to configure your routing tables appropriately.
Your network needs to be configured like this:
Public Subnets:
IGW attached
NAT Gateway
Any other public resources that need to be accessible from the Internet, such as a public load balancer.
Private Subnets:
A route to the NAT Gateway in the public subnet. No route to the IGW.

AWS: ECS Service with Elastic IP

I've created a cluster, VPC, subnet and a Fargate service using the first run wizard of ECS on AWS console and uploaded the image on ECR and deployed successfully.
Now I need the service to access a remote database. So, I need to add the IP in the firewall's whitelist. I allocated an Elastic IP, created a NAT Gateway and updated the router table following this tutorial.
I stopped the task and tried to run it again. But then I could not pull the image from ECR to run a new task caused by the following error message:
CannotPullContainerError: Error response from daemon: Get https://account-id.dkr.ecr.sa-east-1.amazonaws.com/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
My setup:
VPC with CIDR 10.0.0.0/16 (automatically created on ECS wizard)
Subnet with the following router table:
Destination | Target
----------------|-------------
10.0.0.0/16 | local
0.0.0.0/0 | nat-<nat-id>
NAT Gateway, on VPC and subnets that were created on ECS Wizard and the Elastic IP I allocated.
Currently, I'm allowing all traffic in both inbound and outbound rules:
Type | Protocol | Port range | Source | Description - optional
-----|----------|------------|---------|------------------------
All | All | All |0.0.0.0/0| -
What am I missing? Is this the only way I can accomplish what I want? Is there a simpler way to achieve it? I found in Stack Overflow another way to associate an Elastic IP by using Application Load Balancer or Network Load Balancer. Is it a better approach?
The ECS wizard creates a VPC with two public subnets 10.0.0.0/24 and 10.0.1.0/24. They both use a single RT which points to internet gateway (IGW). However, from your question it appears that you've modified it to use NAT.
Sadly, this will not work, as you've already experienced. To rectify the issue, you could create a third subnet (or more if you need for HA). The subnet will be private with no internet connection. Instead it will have a new RT which will route internet traffic to NAT. Your Fargate tasks would be launched in the private subnet(s).
The new RT of the new subnet(s) would be:
Destination | Target
----------------|-------------
10.0.0.0/16 | local
0.0.0.0/0 | nat-<nat-id>
The RT of the two original public subnets, should be modified to route traffic to IGW, like it was originally done:
Destination | Target
----------------|-------------
10.0.0.0/16 | local
0.0.0.0/0 | IGW
I thought of explaining this. you are getting the CannotPullContainerError error is because there is no route to the internet. The traffic to the ECR go through the internet by default.
your Fargate service is running in a private subnet which does not have direct routes to the internet. In order to get internet access, the private subnet where the Fargate task is running should have routes in its route table to route the traffic to the internet via the NatGateway (you have done this already). thereore
Destination | Target
----------------|-------------
10.0.0.0/16 | local
0.0.0.0/0 | Natgateway
The NatGateway simply routes the traffic to the internet gateway. The Nat gateway is deployed in the public subnet and it will have routes to internet via the internet gateway. Therefore the subnet where the Nat Gateway is deployed should have the following route created.
Destination | Target
----------------|-------------
10.0.0.0/16 | local
0.0.0.0/0 | InternetGateway
Note:
You can also talk to ECR privately without going through the internet by creating a Private ECR VPC end point.
Internet Gateway

Amazon NAT gateway not working - Instances not accessible

I run an Elastic Beanstalk setup, with a dynamic amount of servers, with dynamic IP's, an external provider needs to whitelist our IP, so I need to route all my traffic out via a NAT gateway.
I am using the default public VPC, with 3 default subnets.
I have created a new Subnet, and a new NAT gateway, which I have placed on this new subnet.
I have created a new route table for this new subnet, where 0.0.0.0/0 points to an internet gateway.
I have changed the routes from the other 3 default subnets from 0.0.0.0/0 (Internet Gateway) to 0.0.0.0/0 (NAT Gateway).
My instances become inaccessible after i do this, what seems to be the issue, and where can i find some logs?