From the course: Cisco Certified Network Associate (CCNA) v1.1 (200-301) Cert Prep

Unlock this course with a free trial

Join today to access over 24,800 courses taught by industry experts.

Loop guard

Loop guard

From the course: Cisco Certified Network Associate (CCNA) v1.1 (200-301) Cert Prep

Start my 1-month free trial Buy for my team

Loop guard

“

(soft music) - [Instructor] In this video, let's consider another tool that can add some stability to our spanning tree. Specifically, we're going to be considering a feature called loop guard. And loop guard is going to take a port that is not a designated port. In other words, it's a port that should be receiving not sending BPDUs. It's going to take that non-designated port and transition it into a loop inconsistent state if that port stops receiving BPDUs. And recall that a BPDU or a Bridge Protocol Data Unit is originating on our root bridge and it flows throughout the network and it contains information such as the bridge ID of the root bridge and the cost to get back to the root bridge. And these BPDUs originate on the root bridge but when they get to the next top switch, these BPDUs are going to be sent out the designated ports of those next top switches all the way down the tree. So a designated port is going to be sending out a BPDU but we should be receiving BPDUs on root…

Contents