Cisco 3750 Stacking problem

[ericng1983]

Hi there,

I have 2 core cat 3750 switches need to be stack as one. However, I am short of longer stack cable due to the reason that each switch was away from each other by one rack. I decided to stack both the switch by using a cross-over cable I heard this is workable (can be done) but not sure how it should be configure.

Anybody know how should it be configure to stack via an RJ45 cable Instead of a stack cable?

Thank you

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[jeff]

Hello:

It is my understanding that the stack interfaces and stack cables are the only way to truly stack.  However, you can cascade the switches together via an Interswitch link.  I would recommend that you form and etherchannel between switches to provide link redundancy.  This is considered "Old School" , and you will need to keep in mind that both switches are independent bridges and will each require a management address.

If there is a way to configure a port to behave as a stack interface, please let me know.

Regards,

JS

[ericng1983]

Actually I heard some one saying it can stack using RJ45 but not sure I have heard it wrongly or the person who say that actually mean using other method as what you have mention. Erm... Btw are you trying to say the method you suggest can make two switches act as one? Just like having the stack capabilities?

What will be the effect of cascading two switches together? And how to perform interswitch link?

Please advise. Thank you

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[Amit Aneja]

Hi,

It's not possible to stack two 3750 switches using RJ-45 & have them behave as one switch.

They don't support Gigastack design (officially) as well like other switches, 3550, 2900 etc.

As JS mentioned that you could connect them using etherchannel for redundancy. This is the only way you could increase the bandwidth b/w the two switches. But, still you won't be able to get 32 Gbps backplane speed & have them behave as one unit.

Regards,

Amit

[Leo Laohoo]

I have 2 core cat 3750 switches need to be stack as one. However, I am short of longer stack cable due to the reason that each switch was away from each other by one rack. I decided to stack both the switch by using a cross-over cable I heard this is workable (can be done) but not sure how it should be configure.

You are talking about Switch Clustering and with a 3750 it's not worth it.  Switch Clustering is only beneficial if you are trying to manage multiple switch in a cluster using ONE (1) management IP address.  Anything else is purely nuts.

[ericng1983]

So what is the best way to be recommended? Cascading is also something similar with stacking?

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[Leo Laohoo]

So what is the best way to be recommended?

If you have the GigaStacking GBIC then Switch Clustering is OK.  If you have 3750 then you need to use the StackWise.  Not only does StackWise simplifies management and configuration but when you are dealing with EtherChannel StackWise is the way to go.

[ericng1983]

Actually I get a bit confuse between few technology

May I know what is the different between cascade, stack and cluster?

If I am using a cascade cable to join the 3750 switches together, how do I configure the switch?

Many Thanks in advanced.

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[emmanuel.shoroma · Accepted solution]

Hi, Cascade mean connecting them together ( you might use etherchannel to increase badwidth between the them). however, they will still have two separate management IP addresses. Cluster is when you connect them together so that you can use one IP address for management but they still function separately. if you want the switches to work as one, you need to use the stack cable. that's the only way you can make your 3750 work as one switch. If I may ask, what are you trying to address by stacking the cable together?

[ericng1983]

Emmanuel - I guess that was wrongly phrase, what I mean is using an RJ45 cable and do cascading method.

Guys - Great help! I should have a better understanding by now. Thanks for all the replies.

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