The purpose of spanning tree is not to ensure that only a single copy of the frame arrives (although it does do that). It's purpose it to ensure a loop-free environment. There are some loop situations where multiple copies of frames are generated over an over. But there are also situations where the same single frame loops infinitely.
As for explorers, there can be many paths to a destination. Usually the first response from an all routes explorer is considered to be the most efficient and so that path is used. Since the path is predetermined, there is no need for a spanning tree, per se. However, IBM apparently came up with a proprietary spanning tree-like function. For example, setting a pair of parallel bridges in a "spanning tree" configuration means that only one of those two bridges will forward a spanning tree explorer frame. Either way, the source still needs to determine a path to the destination.
I don't know this for sure, but it seems implied that even a pair of bridges running the proprietary IBM spanning tree implementation would both forward an all routes explorer. Just seems to be intended to provide an option to reduce traffic generated by all routes. Sort of like the IOS, which can convert an all routes to a single route.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...