# Spanning Tree Port States

**URL:** https://forum.networklessons.com/t/spanning-tree-port-states/1113
**Category:** Lessons Discussion
**Created:** [December 26, 2016, 11:01pm UTC](https://forum.networklessons.com/t/spanning-tree-port-states/1113 "2016-12-26T23:01:39Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![francescorocco77](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/f/5f9b8f/32.png) [@francescorocco77](https://forum.networklessons.com/u/francescorocco77)
#### Post date: [May 10, 2015, 5:53pm UTC](https://forum.networklessons.com/t/spanning-tree-port-states/1113/4 "2015-05-10T17:53:23Z")

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Hello, Rene  
if we suppose that we have 3 switch..we power on them…after booting,  
the port of each switch connected each other goes into listening ,because they need to do an election…(in this 15 seconds a port is learning if it will be root port,designated port , or non designated port. Once understood, if it wiil be non designated goes into blocking state otherwise it’s going into learning and then forwarding).Now the switch network will be converged…If now I focus at the port in blocking state ,it receive BPDU by a peer designatet port,every 2 sec, and store that bpdu value (here now we can speak of the value of MaxAge-MessageAge..20 sec)..At one time the blocking port doesn’t receive bpdu from it’s designated switch, this one send a TCN to root bridge out it’s root-port, but my blocking port has to wait 20 second( MaxAge-messageAge) before going into listening state and can send out BPDu frame…Meanwhile this switch with this blocking port has to lower the aging time??? But I don’t understand who say to switch ..lower the aging time

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