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Hi Steve, Hi list,

Starting a new thread, 'cause I am interested in others' experience moving off of the default Cisco PVSTP and don't want to high-jack the OP.  We have thought about trying to move off of it to facilitate a multi-vendor network, but find it daunting.  As someone wrote in another list: "Any network engineer who causes a spanning-tree re-convergance during production hours should be fired."  I don't know about being fired, but we have become quite cautious about spanning-trees.  Can anyone share experience, strategies or gotchas around moving off of PVSTP.  I inherited it many years ago, but would not have thought to do anything differently at the time.
thanks,
Dennis Bohn
Manager of Network and Systems
Adelphi University
bohn@adelphi.edu
5168773327


Comments

HI Dennis,

 

I have always made our cores the root bridge for any vlan after a lengthy learning experience ~15 years ago:

 

This example is from Cisco IOS:

 

spanning-tree vlan X,Y,Z priority 8192

spanning-tree vlan X,Y,Z forward-time 12

spanning-tree vlan X,Y,Z max-age 16

 

This code has eliminated the possibility of a deeper switch becoming the root bridge for a particular VLAN.

 

Best practice in my mind.

 

Chad

 

Chad D Burnham

Assistant Director of Telecommunications, Planning and Implementation

University Technology Services - Network Services

University of Denver

2100 S. High St. #112

Denver, CO 80208

Desk Phone: 303-871-4441

Mobile Phone: 303-520-5657

 

 

 

 

From: The EDUCAUSE Network Management Constituent Group Listserv [mailto:NETMAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Dennis Bohn
Sent: Friday, September 14, 2012 9:43 AM
To: NETMAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [NETMAN] Moving off of PVSTP

 

Hi Steve, Hi list,

 

Starting a new thread, 'cause I am interested in others' experience moving off of the default Cisco PVSTP and don't want to high-jack the OP.  We have thought about trying to move off of it to facilitate a multi-vendor network, but find it daunting.  As someone wrote in another list: "Any network engineer who causes a spanning-tree re-convergance during production hours should be fired."  I don't know about being fired, but we have become quite cautious about spanning-trees.  Can anyone share experience, strategies or gotchas around moving off of PVSTP.  I inherited it many years ago, but would not have thought to do anything differently at the time.

thanks,
Dennis Bohn
Manager of Network and Systems
Adelphi University
bohn@adelphi.edu
5168773327

I think you are wise to “respect” spanning tree of any kind, as it can get out of control and cause big problems.

I would start with studying the different individual features and difference between implementation between the two versions.

Then, I would plan on making the changes during Christmas break or maybe Thanksgiving break.

 

If you have spare equipment, you may want to play with it in a lab environment.

The Cisco TAC can also help.

 

If you have specific questions, feel free to share them with the list or off line. We went through the process a number of years ago.

 

Pete M.

 

 

From: The EDUCAUSE Network Management Constituent Group Listserv [mailto:NETMAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Dennis Bohn
Sent: Friday, September 14, 2012 11:43 AM
To: NETMAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [NETMAN] Moving off of PVSTP

 

Hi Steve, Hi list,

 

Starting a new thread, 'cause I am interested in others' experience moving off of the default Cisco PVSTP and don't want to high-jack the OP.  We have thought about trying to move off of it to facilitate a multi-vendor network, but find it daunting.  As someone wrote in another list: "Any network engineer who causes a spanning-tree re-convergance during production hours should be fired."  I don't know about being fired, but we have become quite cautious about spanning-trees.  Can anyone share experience, strategies or gotchas around moving off of PVSTP.  I inherited it many years ago, but would not have thought to do anything differently at the time.

thanks,
Dennis Bohn
Manager of Network and Systems
Adelphi University
bohn@adelphi.edu
5168773327

Message from mark.duling@biola.edu

We changed our campus architecture to be L3 routed links between buildings a while back after getting L3 capable switches in the main data closets.  It reduces spanning-tree domains dramatically.  Are others still finding benefits in having campus wide vlans, or are you finding the cost of L3 switches prohibitive?