Spanning Tree Issues
All switches on a shared network believe all STP information they get from anywhere
No filtering or policy constraints like BGP
Topology changes, or problems in one IPP can have impact on any other interconnected IPPs
Safest to disable STP across interconnect
- could create single point of failure
- trunking might solve this
New IEEE 802.1s and 802.1w enhanced STP standards, tag stacking, may help with this