OTV is mainly (and makes sense) for data centre interconnects. Most low end switches don't support it. Sent from my iPad On 25 Feb 2012, at 11:13, jim ndegwa <ndegwajim@yahoo.com> wrote:

on a somewhat related topic, if you are also looking at extending your VLANs, check out OTV. You can span those switches across disparate datacenters quite nicely

http://routing-bits.com/2011/06/16/cisco-otv-part-i/

From: David Kariuki <kariukidw@gmail.com> To: East Africa Network Operators Group <eanog@lists.my.co.ke> Cc: Skunkworks Mailing List <skunkworks@lists.my.co.ke> Sent: Friday, February 24, 2012 4:42 PM Subject: Re: [EANOG] [Skunkworks] STP convergence & MST

I'd also recommend MSTP (If you really need to use STP that is...). It requires a lot of planning though but you will have no sleepless nights once its up and running.

David

On Fri, Feb 24, 2012 at 4:33 PM, John Gitau <jgitau@gmail.com> wrote: Hey If you're willing to do a little bit more work upfront and have an easier life later, I'd go with MST.

While PVST (pvst+) adopted fast-convergence properties introduced by IEEE RSTP protocol, the core feature of keeping a separate copy of STP per VLAN did not change. Ie it still remained a challenge. Seeing the problems associated with PVST approach, Cisco came with idea of decoupling the concepts of STP instances and VLANs. MST. The initial implementation was called MISTP (Multiple Instances Spanning Tree) and later evolved into IEEE 802.1s standard called MSTP (Multiple Spanning Trees Protocol).

Pvst can also be tuned to achieve faster convergence. Have a look at the design guides below.

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configurati...

http://standards.ieee.org/getieee802/802.1.html

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configurati...

Gitau

Sent from my iPad

On 24 Feb 2012, at 16:17, TheMburu George <themburu@gmail.com> wrote:

...

Hey skunks

I need to implement fastest convergence on VLAN's. One way is implementing PVST (Per VLAN STP) and have preset root bridges, now the question which among the following facilitate faster root bridge election and hence quicker convergence #spanning-tree vlan vlan_no. priority value #spanning-tree vlan vlan_no. root {primary |secondary}

The second way is implement Multiple Spanning Tree (MST), though I havent implemented it and dont know the shortcoming but seems faster and lighter than PVST. Question is how is the experience to those who have implemented it and speed of convergence and fault tolerance

./TheMburu -- Conservatism is the adherence to the old tried against the new untried. _______________________________________________ Skunkworks mailing list Skunkworks@lists.my.co.ke ------------ List info, subscribe/unsubscribe http://lists.my.co.ke/cgi-bin/mailman/listinfo/skunkworks ------------

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