I'm trying to set up the system in the link on Amazon Virtual Private Cloud.
https://docs.google.com/presentation/d/1H3s9O2GnM52cfKWiyt2oK92SSCEU-K1Srz5sw2uuRhU/edit?usp=sharing
My question is "any possible to let TCP server know real TCP Client's IP ?"
I get ip always from load-balancer and no idea about how to get the ip from real client.
Very Thanks.
According to documentation,
Proxy Protocol
The Proxy Protocol header helps you identify the IP address of a client when you use a load balancer configured for TCP/SSL connections. Because load balancers intercept traffic between clients and your back-end instances, the access logs from your back-end instance contain the IP address of the load balancer instead of the originating client. When Proxy Protocol is enabled, the load balancer adds a human-readable format header that contains the connection information, such as the source IP address, destination IP address, and port numbers of the client. The header is then sent to the back-end instance as a part of the request. You can parse the first line of the request to retrieve your client's IP address and the port number.
The Proxy Protocol line is a single line that ends with a carriage return and line feed ("\r\n"). It takes the following form:
PROXY_STRING + single space + INET_PROTOCOL + single space + CLIENT_IP + single space + PROXY_IP + single space + CLIENT_PORT + single space + PROXY_PORT + "\r\n"
The following is an example of the IPv4 Proxy Protocol.
PROXY TCP4 198.51.100.22 203.0.113.7 35646 80\r\n
The Proxy Protocol line for IPv6 takes an identical form, except it begins with TCP6 and the address is in IPv6 format.
The following is an example of the IPv6 Proxy Protocol.
PROXY TCP6 2001:DB8::21f:5bff:febf:ce22:8a2e 2001:DB8::12f:8baa:eafc:ce29:6b2e 35646 80\r\n
If the client connects with IPv6, the address of the proxy in the header will be the public IPv6 address of your load balancer. This IPv6 address matches the IP address that is resolved from your load balancer's DNS name that is prefixed with either ipv6 or dualstack. If the client connects with IPv4, the address of the proxy in the header is the private IPv4 address of the load balancer, which is not resolvable through a DNS lookup outside the EC2-Classic network.
For information about enabling the Proxy Protocol header, see Enable or Disable Proxy Protocol Support.
Related
I have an unmanaged instance group that has 2 VM Instances in it with an external IP Address of, let's say 1.2.3.4 and 1.2.3.5. After that, I created an External TCP LoadBalancer for this instance group (as the backend service). After creating this load balancer, I received the frontend IP Address of that loadBalancer (which I assume is the IP Address of the forwarding rule) and let's say this IP Address is 5.6.7.8. Now, when we create a loadbalancer we need to create health checks and create a firewall rule to allow that health check to communicate with each VMs.. Hence, I created a firewall rule, ingress, allow, to port 80 (by the way everything here is port 80... that's the only port I use) with Source IPV4 ranges are 209.85.204.0/22 209.85.152.0/22 35.191.0.0/16 (port 80) where these IPv4 ranges are available in Google's Documentation page.
Now, the load balancer declares that the backend service are healthy. So then, I wanted to make a firewall rule for my VMs (instance group) that only allow ingress from the frontend IP of the load balancer, that is ingress, allow, source IPv4 ranges 5.6.7.8/32 (again port 80) to my VMs,, thinking that it will work. However, when I input the IP address in my browser, it does not "redirect" to the respective VMs (that is 1.2.3.4 and 1.2.3.5). It only works if i put 0.0.0.0/0 as the source IPv4. Hence, it is kinda useless for having two firewalls (one for healthchecks one for forwarding rule).
The reason I want to do this is because I only want my VMs to receive incoming ingress from the load balancer frontend IP address, such then if i put 1.2.3.4 or 1.2.3.5 in my browser it will not connect. It connects if and only if I put 5.6.7.8.
Is this achievable?
Thank you in advance!!
Edit: All resources are in the same region and zone!
According to the doc, the firewall rule must allow the following source ranges:
130.211.0.0/22
35.191.0.0/16
Also, you can read this doc. The IP 5.6.7.8 is not the source IP that sends to your backend from LB. LB sent to your backend is from the same range used by health check:
35.191.0.0/16 130.211.0.0/22.
Suggestion:
You might use tcpdump to see what IP sends to your VM.
Tag the backend instances "application," and create a firewall rule with the target tag "application" and the source IP range of the allowed clients and Google health check IP ranges.
I am playing with the NLB. One feature is that it can preserve the client source IP. I tested it and it works. However, has anybody been wondering how it works?
Let's say that my home PC is the client for the HTTP request and it is behind the public IP 1.1.1.1
The NLB has an IP of 2.2.2.2 on the public side. The real webserver in the target group is an instance with private IP 192.168.0.10. The instance is also in the public subnet and it has an elastic IP of 2.2.2.10.
I confirmed with my packet capture (tcpdump) on the server that I see requests coming in from 1.1.1.1. I see the response going back to 1.1.1.1 as well. However, my home PC's Wireshark would show traffic to and from 2.2.2.2, and not 2.2.2.10... How's that possible?
From the routing perspective, the server would receive the request from 1.1.1.1 and will send a response back to it. The response would traverse through the IGW, instead of the NLB, and therefore will have 2.2.2.10 when on the Internet. The connection would be rejected by my PC because the response came back from a different IP (2.2.2.10) rather than the original one (2.2.2.2).
Is the NLB somehow tied to the IGW and in this case, the IGW would know to SNAT the response to 2.2.2.2 instead of 2.2.2.10?
Thanks,
Difan
I'm hosting a website on my computer. I enabled port forwarding to port 8080 using the virtual server option ("The Virtual Server option allows you to define a single public port on your router for redirection to an internal LAN IP Address and Private LAN port if required.") so my website can be accessed by typing our router's IP address and then the public port redirecting to my internal IP (xx.xx.xxx.xx:8080). I also have a domain ready and I am trying to configure an A record in the DNS management panel. The target should be an IP address, but it says invalid value in dnsrecord when I type the address and port. It probably doesn't accept the port, but if I don't specify the public port for my internal IP, the website can't be accessed. Any help?
As you stated, your record should be an IP address and not IP:PORT. So just input the xx.xx.xx.xx address and it should work.
The TTL indicates how long the clients should consider the IP address corresponding to the DNS as valid.
The record type A indicates that it is an address record (returning an IP).
I don't know freenom, but I hope this helps you configuring your DNS record.
The default port is 80 so set port forwarding to that
I have an API gateway which is sending requests via the VPC link to Network load balancer(NLB) which is then forwarded to the target instance. As per AWS documentation, when the target group is instance the source ip is passed unfettered to the target instance, but if by ip address then NLB ip address. However even though the target group is set to instance I am still getting NLB ip address.
If you need the source ip, you can map the context variable context.identity.sourceIpto a integration header docs. You will be able to access this header in your server.
The docs for NLB are referring to the proxy protocol 2 support which will allow your to get the source ip of a connection to a nlb. This requires running a web server with proxy protocol enabled (squid/nginx has a flag to enable this). With respect to VPC Links, this ip is not the same as your source ip of a request to your server since the NLB actually sees connections from API Gateway, so enabling this on the NLB will return internal ip addresses of API Gateway.
In swagger it'll look like
...
"requestParameters" : {
"integration.request.header.x-source-ip" : "context.identity.sourceIp",
}
...
There is a web service (in an Intranet environment) what checks the client IP and if it is not a valid IP then refuses the request. Is there any opportunity to cheat at this web service with the IP?
Thank you in advance.
It is prefectly possible to send IP packets with fake IP addresses. However, you won't get a reply because the reply will be directed at the fake IP address. This means that you can't establish TCP connections (upon which HTTP(S) depends) because they require two-way IP traffic.