How can portfast cause a loop ?

Hi What is exact effect of portfast port connected with a switch in loop ? If a new switch is plugged into portfast port in another switch, the effect  could be the new switch will bother STP of core. Is there any effect else ? How can this cause a loop in the network ? I do not understand how to cause the loop without physical loop. Anyone can help to give me some suggestion ? Thank you
eemoonAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

lruiz52Commented:
Portfast skips the STP process and sets port straight to forwarding.  Check the link below to find out about layer 2 switching loops.

http://www.omnisecu.com/cisco-certified-network-associate-ccna/what-is-layer-2-switching-loop.php
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Switches / Hubs

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.