I am always confused about these three concepts.
I just want to know the basic understanding of this three features of STP.
where should i use and which mode i can configure this ?
I referred cisco website for the same but still not cleared about it ............
Please share the knowledge . It would be great help for getting cleared this concepts ....................
Loopguard:- Unidirectional link failures may cause a root port or alternate port to become designated as root if BPDUs are absent. Some software failures may introduce temporary loops in the network. The loop guard feature checks if a root port or an alternate root port receives BPDUs. If the port is receiving BPDUs, the loop guard feature puts the port into an inconsistent state until it starts receiving BPDUs again.
BPDU Guard:-BPDUGuard enables on access port which helps the switches to put the port in shut down mode once it receives the superior BPDU. e.g. In case of metro ethernet, SP puts switches at customer building and make that switch ar root bridge. Now imagine if some other customer switch sends a superior BPDU then the STP need to be converged again and lead of serious issues.
Rootguard:- It is enabled on the designated ports of root switch, so that if those ports listen to the superior BPDU then put that port in inconsistent state.