I've got a setup on Windows Server 2012 R2, using IIS8.0 which passes certain requests through to a custom backend using Application Request Rerouting.
The backend is only listening on IPv4 on port 20000, and my rewrite rule for ARR is as such:
- Pattern: ^BackEndService/(.*)
- Action type: Rewrite
- Rewrite URL:
http://127.0.0.1:20000/{R:1}
- Append Query String: True
- Stop processing of subsequent rules: True
This should therefore forward requests made from my frontend as, e.g. /BackEndService/getName?user=tom to http://127.0.0.1:20000/getName?user=tom
What I'm seeing, however, is a huge delay in the request reaching my backend - 120s.
I've seen this when using Nginx as a test server, but only when proxy-passing to localhost:20000 - proxy passing to 127.0.0.1:20000
works without this timeout. This leads me to suspect it's an IPv4/6 issue.
Has anyone else seen this before and, moreover, knows how to fix it?
Thanks