Tag Archives: ARP

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 »

Dynamic ARP Inspection (DAI) Concept/Attack Example and Implementation

Dynamic ARP Inspection is a security feature that rejects invalid and malicious ARP packets, by using DAI we can prevent ARP Poisoning/Spoofing Attacks. The Address Resolution Protocol works the following way “” wants to communicate with “” however the switch does not know how to reach the layer 3 address as switches only understands L2… Read More »