Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

STP - Port status

Status
Not open for further replies.

1028

Technical User
Apr 18, 2002
15
US
Hello.

Can I get some help about a question related to Port-status-change of STP.

I was wondering if Port-status-change (Listening-> Learning-> Forwarding or Disabled/Blocked) is only applied to a STP-enabled switch. If STP disabled or w/ non-STP switch, shouldn't the port-status-change occur like above?

Thank you,
Sun
 
Spanning-Tree Protocol (STP) is a Layer 2 protocol designed to run on bridges and switches. The specification for STP is called 802.1d. The main purpose of STP is to ensure that you do not run into a loop situation when you have redundant paths in your network. If STP is disabled or does not exist, then the switch should be in forwarding state right off the bat.
 
Hello.

Thank you for your explanation.
I understand. But, please let me ask further; I have a switch (not cisco's) whose ports are going through Listening and Learning status unless forward-delay parameter is set to zero whether STP is enabled or not. If Listening and Learning status are only applied to STP-enabled switch, in case of STP-disabled, shouldn't they go through Listening and Learning status? (though ports settle in Fwd state finally, I'm wondering why they are going through Listening and Learnig state. Also, isn't Forward-delay parameter only applied to STP? Why does Forward-delay seem to work in case of STP-disabled?)
 
I'm not sure what your getting at with this question. If you have a switch that is going throuhg listening-> learning, then it would seem that this switch is doing STP. Regardless if it's been disabled or not. Seems like the software will not let you totally disable STP. Is this a problem your having with a switch in your network?
 
Yes, we have a switch whose ports are going through listening -> learning even though STP is disabled. And, since ports are going through these states, if once a cable diconnected and then re-connected, it seems to take more time to be able to communicate data.

So, I can conclude that the switch can't disable STP completely.

Your explanation helps me a lot.
Thank you.
Sun
 
Try checking the switch docs and look for a command similar to Cisco Portfast command... maybe you need to force them into Forwarding mode...

Mike
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top