Will the 2960s in a stack pair do what I require? *with diagram*

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Apr 8th, 2010
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Please see attached visio. Existing tab shows the switches in their current configuration using uplinks.


Using only 2 new switches (a pair of 2960s in a stack) I would like to add resilience as shown. Is this possible or do I need something different?


Thanks for any time and advice.


Other suggestions to use existing switches very welcome to improve resilience of a single point of failure.


Thanks


Paul

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Correct Answer by Leo Laohoo about 7 years 1 month ago

By the way, forgot to mention that if you are indeed using 2950 or 2960 switches as your aggregate switches, forget about Etherchannel because it won't work.  Etherchannel would work if your uplink switches is one logical switch.  Like I mentioned in previous post, only the 2960S and 3750/3750E/3750X are capable of doing that because of the SmartStack technology.


There are difficulties with Etherchannel when you use Gigastacking GBIC and/or switch clustering.

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Jon Marshall Thu, 04/08/2010 - 07:59
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Not all of use can read visios, please post as a .jpg/.png


Jon

Leo Laohoo Thu, 04/08/2010 - 16:02
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Wow.  I've haven't seen a network cabled up like this for a long, long time.  Any reason why the switches are "lollipop-ed" like this?  Are they in different floors?  Different data racks?


If they are all in the same floor/data racks, I'd consider consolidating all the switch uplinks to a pair of 2960S or 3750.  Both the 2960S and the 3750/3750E/3750X can be stacked.


Note:  Your diagram shows your switches to be using "switch cluster" and not stack.


Best Regards/Leo

goldiethedog Fri, 04/09/2010 - 03:02
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"If they are all in the same floor/data racks, I'd consider consolidating all the switch uplinks to a pair of 2960S or 3750.  Both the 2960S and the 3750/3750E/3750X can be stacked."


They are all in the same room in 3 racks as shown in the first diagram.


I'm just looking for a yes or a no as to whether I would be able to cable them up like in the 2nd diagram with the 2960S.


If not which switches do I need to do this?

shailesh.h Fri, 04/09/2010 - 07:19
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What exactly you want to achieve

1. Resilience


But couple of questions to answer


1. Do you have estimation of what would be uplink bandwidth requirement

2. How much would be distance between central switches second switches

3. why you want to cascade and making three tier instead you can make it two tier (this will save the ports of intermediate switch and chances of failure)

4. Do you want to dedicate centralized switches for central connectivity

5. can be used etherchannel technology if more bandwidth required...

6. Do you have budget for new switches or constraint to use existing switches

7. What would be VLAN requirement for each sw


Kindly consider and respond back so that we can progress on propose topology

goldiethedog Fri, 04/09/2010 - 07:30
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What exactly you want to achieve

1. Resilience - Correct


But couple of questions to answer


1. Do you have estimation of what would be uplink bandwidth requirement - there are no applications requiring high bandwidth - there is WAN traffic, local exchange 2003 and file server.

2. How much would be distance between central switches second switches - all switches are within a few metres of each other.

3. why you want to cascade and making three tier instead you can make it two tier (this will save the ports of intermediate switch and chances of failure) - yes you are correct, I don't need to cascade the switches. Two tier is good.

4. Do you want to dedicate centralized switches for central connectivity - centralised switch(s) will also provide Gbit links for servers using Teamed NIC's across the switch with only one active.

5. can be used etherchannel technology if more bandwidth required...- if I need to use etherchannel to achieve goal then OK.

6. Do you have budget for new switches or constraint to use existing switches - constraint to use existing switches but want to add minimum hardware required to make this work, ie a pair of 2960S in a stacked pair.

7. What would be VLAN requirement for each sw - VLAN's are flat - ie they are not used.


I also do not require the switch to act as router. Reslilience is the only requirement at present.


Kindly consider and respond back so that we can progress on propose topology - thankyou for your time.

goldiethedog Mon, 04/12/2010 - 01:23
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Anybody able to answer this relatively simple question?


Thanks

shailesh.h Mon, 04/12/2010 - 03:14
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I tried to simplify the topology and provid

ed answer in the diagram attached.. this will provide redundancy and max port availability for you..

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Leo Laohoo Mon, 04/12/2010 - 17:58
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Paul,


Of course you can cable up to the way you proposed.  But I'll tell you one thing ... STP is going to be a b1tch!


Using a 2950 or plain 2960 is something I wouldn't use.  I would consider looking for a switch that'll support StackWise like the 2960S and 3750/3750X/3750E.

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Leo Laohoo Tue, 04/13/2010 - 15:38
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By the way, forgot to mention that if you are indeed using 2950 or 2960 switches as your aggregate switches, forget about Etherchannel because it won't work.  Etherchannel would work if your uplink switches is one logical switch.  Like I mentioned in previous post, only the 2960S and 3750/3750E/3750X are capable of doing that because of the SmartStack technology.


There are difficulties with Etherchannel when you use Gigastacking GBIC and/or switch clustering.

Leo Laohoo Wed, 04/14/2010 - 15:17
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Thanks for the rating.

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