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Author Topic: Problem with 3 8600 design.  (Read 4075 times)

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Offline kien241

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Problem with 3 8600 design.
« on: August 04, 2013, 03:53:32 PM »
Hi everyone,
I'm new to Avaya/Nortel so design SMLT is something i'm not sure.
Because my customer have 3 core and i understand that cluster only come in pair. So i have to use triangle topology. But my customer they have a lot of site that connect random to any 8600s base on location ( 2 nearest 8600s). And i don't know if this design can cause loop. As i understand cluster act as a switch.

If this design can cause loop. Can you suggest a design.
Many thanks
Sorry about my English. I'm native English speaker.


Offline Paul L

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Re: Problem with 3 8600 design.
« Reply #1 on: August 04, 2013, 09:10:21 PM »
yes, you would have a loop in that design.  Unless you did Layer 3 OSPF routing at the edge. but that isn't ideal

from your diagram, I wouldn't connect any secondary devices to 8600c.  I would connect that switch on the left to 8600A and 8600B.

or, create an MLT from that single switch to 8600c
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Offline kien241

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Re: Problem with 3 8600 design.
« Reply #2 on: August 04, 2013, 09:22:26 PM »
Hi Paul L,
Thank you for your reply.
I understand this topologies is something not recommended. But their fiber cable is ready. The problem right now is design the topology.
All other switch is 5000 series.
I think the last design is layer3 core using OSPF and all other switch use static route ( no license ) with out any SMLT.

Offline Paul L

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Re: Problem with 3 8600 design.
« Reply #3 on: August 04, 2013, 09:26:47 PM »
you could also make the IST cluster between 8600A and 8600C.

but not sure if 8600A and 8600B need to be the IST switch cluster.

is this network all within one building, or a spread out campus?  If you don't have all your edge devices connecting to the IST switch cluster then you don't need to make an IST.  Just make an OSPF enabled network
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Offline kien241

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Re: Problem with 3 8600 design.
« Reply #4 on: August 04, 2013, 09:59:55 PM »
Yeah it spread out the campus.
There are many site, some connect to A+B, some connect to A+C and B+C.
I think i will use OSPF. I want to try SMLT so much :(

Offline Paul L

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Re: Problem with 3 8600 design.
« Reply #5 on: August 04, 2013, 10:27:48 PM »
I would agree, use OSPF.

SMLT is only good if you have a perfectly symmetrical network of all edge devices connecting to an IST switch cluster.
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Offline kien241

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Re: Problem with 3 8600 design.
« Reply #6 on: August 05, 2013, 12:02:02 AM »
Thanks for your advice Paul L
But seem that my customer want to use SMLT with site that connect to A+B and use layer 3 static route with site connect to B+C and A+C.
But can i use the topology from post 1 with SLPP to prevent loop? SLPP and spaning tree with one is better and more simple?

Offline Paul L

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Re: Problem with 3 8600 design.
« Reply #7 on: August 05, 2013, 09:17:59 AM »
you won't be able to use either...

1. SLPP is meant to protect against edge loops and mis-configs mlt loops.  Won't help you in this case.
2. STP won't help either because STP is disabled on SMLT ports.

if your customer wants to keep that topology your best option is to have one liber link on that switch disabled as a cold standby.



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Offline Dominik

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Re: Problem with 3 8600 design.
« Reply #8 on: August 05, 2013, 09:21:47 AM »
I would recommand to make an etxtra Patch for the switches that ends at site C to A/B so that all edgeswitches have one connection to A and one Connetion to B.
At the end of the day you have a much more straight forward design and debugging is also more easy.

Good Luck
Itīs always the networks fault!
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