- Bronze, 100 points or more
Hi every body!
Let say we just installed a switched network. Stp is configured on all switches.
Once the root switch is elected, every switch will detrmine its root port , designated port and blocked port. All root ports and designated ports are put in forwarding state ( i.e these ports at this momentm,do not go through listening state,learning states).
Network is converged.
Let focus on switch (sw1) in the switched network.
Sw1 f0/1 is connected to host.
we turn this host off and then turn it back on.Following steps will occur:
1)Sw1 will decide if its f0/1 is designated port.
2) having decided f0/1 is designated port, switch1 will put this f0/1 into transitory states i.e listening, learning.
3) After these transitory states, port f0/1 finally gets into forwarding state.
It appears to me, if the root switch remain same ,then switch 's designated port,connected to host, will go through listeing and learning states one that port becomes active.
Switch only put its designated port into forwarding state without listening and learning states when it participates in root switch election.
Is it correct concept?
thanks a nd have a nice day!
My understanding is that if the network is powered up the listening/learning/forwarding states do not apply but i could be wrong about this.
While the root and designated ports are being decided on no ports are actually blocking. Only once the topology has converged are there any blocking ports.
If there is then a topology change then any blocked ports that need to be put in a forwarding state then need to go through the listening/learning/forwarding states in 802.1d.
This has always been my understanding.
Edit - apologies for the original post about portfast, should have known you would be aware of it.
If SW1 fa0/1 is connected to a host you should configure that port with portfast enabled. With portfast enabled the port does not go through the listening/learning phases, it goes straight to forwarding.