Sometimes, everything appears to be configured perfectly, but clients will still not connect. In this kind of situation, things can get pretty hairy, and troubleshooting this further is not for the timid. The next steps involve tracing, where we can collect extremely detailed info about what's going on.
To perform a trace on the URA server, go to the Dashboard view and click on Start Tracing on the Tasks pane. If you have multiple servers in a cluster or multisite, you need to click on one of them to get the trace task to show up. The trace dialog box allows you to select whether you want to create a new log, append to an existing one, or run in circular mode. Circular mode is very useful for a situation where an issue occurs rarely, requiring you to run a trace over a long period of time. In such a situation, when the trace file reaches a size of 250 MB, it will purge old data from the beginning of the trace file. When whatever issue you're trying to investigate occurs...