We have developed two different Web API application assume that A and B and both are hosted in Same servers(Server X & Y) and we are using Load Balancer. A connects with B for getting the Data and the DB interactions are done in B Application.
So If application A wants to get any data it has to call application B. We are using Mutual TLS(TLS 1.2) concept for authentication.
To call B from A we need to pass client certificate for authentication. The Certificate based authentication are done in IIS level.
Sometimes the Handshake is happening properly and we are able to get data. But intermittently we are getting 401 UnAuthorized issue even if we are passing valid SYST client certificate.
We verified both the server's IIS configuration as well everything appears same.
So we were unable to understand what is the actual cause for this Intermittent behavior. Can Someone help us what could be the possible reason.