A new command to figure out ports


Recently in a project as we were doing the setup of the system, our hosting provider made a typo in one of the MANY ports that our solution uses and it cause a lot of confussion.

When creating the VIP (Virtual IPs) and ports mapping and the ports got flipped. Our hosting provider gave us a document saying this are your servers:

IP server service VIP for live VIP for auth IP for live IP for auth

But we found out it was reversed, .120 was auth and .121 was live.

So after a lot arguing and a lot of hours of explaining what happened, the question was

How to test where the VIPs are pointing?

I had the need to find a way to bring down the server and effectively test that we are hitting a particular server in a specific port, not through the ports that are used by the server and services because sometimes they may not necessarily tell me if I am hitting auth. My options:

  • Check the access log in the web server
  • Create different data in auth and live (a user or a product that exists in auth but not in live)
  • Enable accesslog trace in the app server

Find a way to test without the app server layer?


From Auth:

  1. logon to auth at
  2. nc -l 5001

From a client try:

  2. in auth, check the output of the nc command