Dear colleagues, In this article on RIPE Labs, Benoit Donnet and Pascal Merindol investigate the various relationships between MPLS tunnels and standard probing techniques (i.e., ping and traceroute). They investigate several possible MPLS configurations and explain how they interact with measurement techniques. There is also an external link to an online platform allowing users to test their MPLS configuration: https://labs.ripe.net/Members/benoit_donnet/gunfight-at-ok-corral-mpls-vs-pr... Kind regards, Mirjam Kühne RIPE NCC