Patching Nginx to ip_hash 4 octets instead of 3 - nginx

Question

I'm currently running two back end servers on my network and load balancing with Nginx on Windows.
I am load testing the system at the moment however all of my traffic is directed at one server. This is because the ip_hash algorithm sorts traffics by the first 3 octets i.e. 111.222.333.XXX
This is a problem because all of the traffic I am aiming at the server has the same base address (The same first 3 octets) therefore none of my traffic is going to the other server. Does anyone know a way to patch or change the ip_hash algorithm to filter through 4 octets.
Thanks

Answer 1

Nginx open source version supports the hash directive that may work similarly (not exactly the same though) to the sticky session mechanism provided by commercial version:
The generic hash method: the server to which a request is sent is
determined from a user-defined key which may be a text, variable, or
their combination. For example, the key may be a source IP and port,
or URI:
upstream backend {
hash $request_uri consistent;
server backend1.example.com;
server backend2.example.com;
}
https://www.nginx.com/resources/admin-guide/load-balancer/
So how do you use 4 octets from IPv4 with the hash method? Let's find how to get the client IP from the Embedded Variables section http://nginx.org/en/docs/http/ngx_http_core_module.html#variables
$remote_addr client address
So the code looks like:
upstream backend {
hash $remote_addr consistent;
server backend1.example.com;
server backend2.example.com;
}
UPDATE:
If take a look at the Stream module (TCP proxy), the very first example shows exact the same approach:
upstream backend {
hash $remote_addr consistent;
server backend1.example.com:12345 weight=5;
server backend2.example.com:12345;
server unix:/tmp/backend3;
}
server {
listen 12346;
proxy_pass backend;
}