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Spantree Portfast

How do I configure Cat5000 port so it can connect veryfast and it should send and receive BPDU's ?

Community Member

Re: Spantree Portfast

As you said in your e-mail you need to configure portfast on the port. What is connected to it? Do not configure portfast if there is a hub connected as loops will occur.

Spanning Tree will be enabled by default on the port so you need not worry about that.

set spantree portfast (mod/num) enable


set spantree portfast 3/1 enable - if you wanted to configure port 3/1.


Community Member

Re: Spantree Portfast

Sorry one other thing, all portfast will do is stop the port participating in the listening and learning states of STP. These last 15 secs each so the port will be available in 20 seconds as appose to the usual 50.


Community Member

Re: Spantree Portfast

Portfast will allow the port to come up immediately. STP will not be running on a port with portfast enabled.


Community Member

Re: Spantree Portfast


I have connected router on one of the port of Cat5000 and even router is doing bridging, I want to configure Cat5000 port so that it should not take usual 45 sec to go forwarding state and same time I want the port should send and recive BPDU.



Re: Spantree Portfast

This is not correct. Port with portfast enabled is still running STP, it just skips the initial listening and learning phase.



Community Member

Re: Spantree Portfast


You can configure portfast with

set spantree portfast

mollari-2> (enable) set spantree ?

backbonefast Enable or disable fast convergence

disable Disable spanning tree

enable Enable spanning tree

fwddelay Set spantree forward delay

hello Set spantree hello interval

maxage Set spantree max aging time

multicast-address Set multicast address type for trbrf's

portcost Set spantree port cost

portfast Set spantree port fast start

portpri Set spantree port priority

portstate Set spantree logical port state

portvlancost Set spantree port cost per vlan

portvlanpri Set spantree port vlan priority

priority Set spantree priority

root Set switch as primary or secondary root

uplinkfast Enable or disable uplinkfast groups

mollari-2> (enable) set spantree portfast ?

Token Ring TRCRF vlan number

Module number and Port number(s)

bpdu-guard Portfast BPDU guard

mollari-2> (enable) set spantree portfast

Spanning-tree PortFast causes a port to enter the spanning-tree forwarding state immediately, bypassing the listening and learning states. You can use PortFast on switch ports connected to a single workstation or server to allow those devices to connect to the network immediately, rather than waiting for the port to transition from the listening and learning states to the forwarding state.

Caution PortFast should be used only when connecting a single end station to a switch port. If you enable PortFast on a port connected to another networking device, such as a switch, you can create network loops.

For full detail refer this link.



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