How to identify route loops

Question

This is a question asked to one of my friend in an interview. Just looking on how people would approach to identify the issue.

In a local network there is a routing problem either due to congestion or due to routing loops. You identify it when you see there is a delay from a sending machine. How will you identify what is the issue is ? a) by analyzing from sending machine b) by analyzing from routers

Thank You,

Answer 1

It seems like the question was not to get right answer , but to see if the guy knows networking. You can not have loop in the local network (lan). You can have a routing loop on the way to some destination. You can identify loop by running traceroute command or mtr command.