Process for testing connectivity in new configurations

This is something we've discussed in the past in the context of TLS conversions, but I didn't see it tracked directly. When we're rolling out new configurations that could break connectivity, it would be helpful to be able to test the new configuration with a special process that will force and track a connection from all of the client and server processes. We could use this when converting to TLS, to make sure that every process has a valid cert and will accept the server certs. We could also use this when deploying to a new physical location to test basic connectivity and ACLs.

The issue names no files, tests, or entry points. Start by tracing how client and server processes establish connections and how configuration changes are applied; completion should be a testable process that forces and records connectivity across all processes, including TLS certificate acceptance and ACL checks.

Written by the indexing model from the issue text.