These configurations add additional connections between the GbESM modules and the Core
switches, using a mesh topology. This topology includes loops on most of the VLANs used,
and therefore requires the use of Spanning Tree Protocol (STP). Testing was performed
using the original STP (802.1D) as well as Rapid Spanning Tree and Multiple Spanning Tree
(802.1w and s). You can find more information about this configuration in 7.7, “Advanced
Layer 2 topology sample configurations