Spanning Tree Flashcards
What does the 5 mean in this command?
>ip route 0.0.0.0 0.0.0.0 10.10.20.3 5
administrative distance (lowest number has highest priority)
Connected links have what Administrative Distance?
0 (the best)
Does Layer 2 have a TTL field in its Ethernet header?
No, Layer 2 does not have a Time To Life Field.
What is the main purpose of Spanning Tree Protocol
It prevents Layer 2 loops, by detecting potential loops and blocks ports to prevent said loops.
What is a negative thing about Spanning Tree?
limits the amount of bandwidth you have by shutting down interfaces that are actually physically cabled.
What are Bridge Protocol Data Units?
This is what switches send out on all ports when first online to detect other switches and potential loops.
When a switch is first online, what state is it in?
Blocking
The BPDU contains the switch’s _____ which uniquely identifies the switch on the LAN
Bridge ID
What 2 things comprise the Bridge ID?
The switches unique MAC address and Bridge Priority Value
How is the Root Bridge determined?
The switch with the LOWEST Bridge Priority
How does a switch choose the best path towards the Root Bridge
the path with highest bandwidth links cost the least, so they are chosen first.
Each switch’s exit interface on the lowest cost path to the Root Bridge is selected as its _______
Root Port. Each switch only has ONE Root Port.
All ports on the Root Bridge are ____ ports
Designated ports. They are connected to root ports on the switch
Which version of Spanning Tree has load balancing
802.1s Multiple Spanning Tree Protocol
What does enabling Portfast do?
Transitions a port that you are sure is never going to loop into a forwarding state immediately.
