I have a setup with a couple of services running in ECS (separate frontends and backends). And now I have the requirement that outbound requests from the backends to some third part APIs needs to have an static (elastic) IP.
As I'm quite the novice with networking I've been following this guide, for basically routing requests to given IP-addresses through the NAT.
Setup:
One VPC
3 subnets (2 for ECS services, the third for the NAT) - All public(?)
Application load balancers for the services.
Routing to the load balancers through Route53.
The way I've been testing it is to either route all traffic, or traffic to my local IP, in the main routing table through the NAT gateway instead of the internet gateway directly. And in both cases, when I try to access either a frontend or server it never responds. And I don't see any traffic in the monitoring-tab for the NAT either. If I just route the traffic directly to the IGW from the main routing table it obviously still work.
So I'd really appreciate some help here since I'm not sure if it's my setup that's not compatible with the above solution, I'm doing something wrong of just overlooking something.
Edit: Did the sensible thing, as pointed out, and placed the services in private subnets.
If you have all your ECS tasks in the public subnet, how are you going to mask all of them behind the NAT? Even my cat knows this.
Related
I am trying to connect to an RDS Instance from my local machine through a VPC Peering connection. In my AWS Account I have two VPCs: VPC1 is connected to my local network via DirectConnect, VPC2 isn't. VPC2 contains all of my infrastructure and the idea is that if I want to connect to that infrastructure from my local machine I need to work through VPC1.
I have configured a route in the peering connection to forward IP based requests to VPC2 for a given address range. This doesn't really help me for RDS though because I don't know what the IP Address for RDS is, only the endpoint. I am guessing that there is some combination of DNS/Routing/Networking/Peering that will solve this problem but I haven't found any documentation that describes how to solve this issue.
Has anyone solved this issue before, or know of any documentation that describes what needs to be done?
Update:
The exact problem is that I can't connect to the RDS instance from my local machine. For example, if I use the RDS Endpoint as the server for my connection, the Sql Client I am using simply can't connect with a timeout error. My suspicion is that traffic is not being routed to VPC2 correctly but I don't know how to prove that.
As far as DNS goes, I am not sure how OnPrem is setup however I have 4 hosted zones in Route53 with a variety of URLs. Items that I setup in Route53 I am able to resolve by host name on my local.
Likewise, I am not sure how the network has been configured with DirectConnect (full VPN tunnel or otherwise).
As far as DNS and the network connections between AWS go though, that stuff works. I am able to resolve pieces of infrastructure in VPC1 fine I just (seemingly) can't get traffic to move across the Peering Connection in the way that I would expect.
I think the problem is that you think you can access vpc2 resources from on-prem just b/c you have direct connect to vpc1. What vpc-peering is giving you is access from vpc1 to vpc2 via private ip addresses. In your case you want vpc1 to act like a router to just transit your request from on-prem to vpc2. It does not work that way.
What are your options:
You could have a host vpc1 access vpc2 (like a bastion host) and you could ssh into that one first.
If possible, you can create a vpn connection from on-prem to vpc2.
And there are more complex solutions via transit gateway.
The doc here talks about vpc-peering limitations, it will basically explain that transitive connections like you want won't work: https://docs.aws.amazon.com/vpc/latest/peering/vpc-peering-basics.html
AWS scenario documentation to reach db mentions option 1 here: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_VPC.Scenarios.html
Sorry for the Japanese material.
I think VPC1 and VPC2 cannot communicate even if you configure routing. So as long as communication is impossible, configuring DNS will not accomplish the goal, I guess.
AWS Solutions Architect ブログ: VPC Peeringの使いどころとTips等々
VPC Peering provides peering, not routing between multiple VPCs, so if you are peering 3 or more VPCs or connecting to locations outside of AWS via VPN or DirectConnect, even if you set the Routing Table appropriately for each, there will be no IP layer routing to networks more than 2 hops away. Even if you configure the Routing Table appropriately, there will be no IP layer routing to networks more than 2 hops away. Workarounds such as using proxies or stepping stones are required as before.
Translated with www.DeepL.com/Translator (free version)
Could PrivateLink help you achieve your goal?
AWS-40_AWS_Summit_Online_2020_NET01.pdf
Along the example on page 42:
local network --> Direct Connect --> VPC Endpoint (in VPC1) --> NLB (in VPC2) --> RDS (in VPC2)
For example, when I deploy two AWS EC2 instances in same VPC and same subnet, that two instances connect through internet using public IP?
I already know that traffic flows referring to route table and my current route table sends all traffic except between private IP to internet gateway.
By the way, I wonder if those "all traffic except between private IP" includes AWS public IP.
In this situation, Does AWS automatically route traffic just inside VPC or not??
Yes, all traffic between the EC2 instances within the same VPC will be routed using internal, private IP obtained from the private DNS.
You can find more in the VPC international DNS here https://docs.aws.amazon.com/vpc/latest/userguide/vpc-dns.html#vpc-dns-viewing
Best, Stefan
The question is a little confusing, but I think I understand. Quick rephrasing:
How does traffic route for EC2 Instances.
If traffic has to go to the internet, then it will. There are techniques where this is done on purpose, such as hairpinning, and if this is your intention, there shouldn't be any problem with doing something like this.
AWS has a 'Backend' (Sometimes called a backbone) network. All communication to EC2 Instances, or Amazon Services in General, should be routed on the AWS Backbone.
I had a little trouble locating a doc with the exact wording, but this doc covers it a bit. Please remember that the AWS Backbone is fast, so it is a good thing to use it.
https://docs.aws.amazon.com/vpc/latest/userguide/how-it-works.html
so currently in our infrastructure we are using ECS with an application load balancer for inbound traffic and a NAT gateway for outbound traffic. I am looking to configure both inbound and outbound traffic to have the same public IP address but I am not sure how this is done as I've tried may different ways to achieve this but nothing seemed to have worked. If we take a look at the below image our infrastructure is similar except that we us EC2 and not fargate as we prefer to maintain our own instances
Screen shot
I would be very thankful if anyone could please help me out with this
I don’t think this is possible. External traffic is always routed though a NAT gateway, and incoming either though unknown number of ever changing load balancers or directly to IP of the e.g. EC2 instance.
I have a PHP + Apache application running in ECS with an Application Load Balance sitting in front of it. Everything works fine except when the application makes request to itself and the request times out.
Let's say the URL to reach the application is www.app.com and in PHP I use Guzzle to send requests to www.app.com but that request will always time out.
I suspect it is a networking issue with ALB but I do not know how I can go about fixing it. Any help please?
Thanks.
As you're using ECS I would recommend replacing calls to a public load balancer with a service mesh instead to allow your application to keep all HTTP(S) traffic internal to the network. This will improve both security and performance (latency is reduced). AWS has an existing product that integrates with ECS to allow this functionality named App Mesh/
Alternatively if you want to stick with what you currently have setup you will need to check the following functionality:
If the hosts are ECS hosts are private then they will need to connect outbound by using a NAT Gateway/NAT Instance in the routing table for the 0.0.0.0/0 route. For Fargate this will depend on if the container is public or private.
If the host/container is public it will need the internet gateway added to its route table for the 0.0.0.0/0 route. Even if inbound access from the ALB to the host is private the host will always speak outbound to the internet via an internet gateway.
Ensure that inbound/outbound security groups allow access to either HTTP or HTTPS
This is the first time I've tried to setup the AWS VPN attached to a transit gateway. I've tested using openswan and it worked like a charm. But the issue is now I am trying to set it up for our premise network which is behind a NAT device. I am trying to comprehend why the tunnel are still down and the network people from the onpremise side are not helping much (they said they've configured the customer gateway and that's it) .
Basically they have given me a CIDR range (/30) to where I need to NAT first all traffics before routing them to onprem and with that CIDR range I could not even create a subnet (invalid CIDR range for the subnet). I have also gotten the static routes which I've added to the transit gateway routes.
Is there a way to NAT traffic from a VPC to a specific network (AWS side in my case to 10.x.x.x/30) before sending the traffic over the tunnel to onpremise. I could not find a way to setup that up.
And also the onpremise network people are not helping much since they said they've setup everything on their side and waiting for me to bring the tunnel up. Is there something am I missing, in my previous AWS VPN setup, the initiator to bring the tunnel was always from the customer gateway side.
/palmer
In this case the vpn will be always initiate from the on premise side for completion.
you need to prepare a cgw and create a s2s vpn connection with those cgw and share the config information s2s with your on premise colleague .
Also for nat in vpc you can use the nat gateway for one way nat.