Send custom headers to the application to check client.ip, server.ip, local.ip & remote.ip

varnish_proxy_support_custom_headers.vcl

vcl 4.0;

backend default {
    .host = "10.10.10.53";
    .port = "80";
}

sub vcl_recv {
	set req.http.x-clientip = client.ip;
	set req.http.x-serverip = server.ip;
	set req.http.x-localip = local.ip;
	set req.http.x-remoteip = remote.ip;
	return(pass);
}