Tag Archives: STP

BPDU Filter and its Potential to Cause a Network Loop

Spanning-tree “BPDU Filter” works similar to “BPDU Guard”, as it allows you to block BPDU’s. The major difference is that “BPDU Guard” will place an interface that receives the BPDU into an “err-disabled” state pretty much protecting the violating port while “BPDU Filter” just “filters” it leaving the port to stay up. If a user… Read More »

BPDU Guard Concept, STP Attack and Mitigation

BPDU Guard, BPDU Filter, Root Guard and Loop Guard are all considered spanning tree security features, they all have different characteristics as to what they protect and how they work. Spanning tree attacks can harm the data-plane at Layer 2 therefore using spanning tree security we can mitigate “Man in the Middle” type attacks, protect… Read More »