In many architectures there are load-balancing mechanisms such as ECMP routing or LAG between various interfaces. This load-balancing is usually per-flow, based on a hash of various criteria, such as source/destination address, protocol, port information, etc. What I'm wondering is, how do you troubleshoot non-deterministic routing situations like this?
For example, in a deterministic routing scenario where traffic takes only one path, there can be cases of packet loss or increased delay on a link, and it's relatively easy to identify this. If this happened in a non-deterministic routing scenario, I imagine identifying problems with a particular member interface could be difficult to discern.
Obviously, in normal situations, there would be no need for this, but I'm wondering if there are any commands on platforms like Cisco IOS (XE, XR, etc.) or JunOS, etc. which could reveal the result of the hashing algorithm, or if anyone has experience with issues like these and has a particular troubleshooting methodology for it.