Hello, One thing to keep in mind is that even if you escape being process switched you still have ECMP and variants to contend with. Some vendors reliably switch packets through certain paths based on source/destination hashes. This means a probe THROUGH a router using a single source address could well report good things while an adjacent source prefix could be screwed by riding a congested path. The only way to be absolutely sure is to either stop using ECMP or run your tests from enough devices to be hashed over all possible paths. All the above in mind, ICMP is quite useful and while it is not 100% accurate it is a pretty good way to identify possible issues. Regards, Blaine