Doubt about Stp

[pradyumnayadavgla@gmail.com]

Dear Team,

Can u tell me about how to run STP  for preventing looping without blocking any port in a redundant network .

Eg. suppose we have five switches and these are connected like ring network.. 

it's question asked me in interview and  I told him that this is not possible..so please suggest me that is this possible if yes then could we do this.

[mlund]

Hi

I had also said it's not possible, unless you are using layer3 between the switches instead of layer2.

Because then you have spanning-tree running on each switch but not between the switches.

/Mikael

[pradyumnayadavgla@gmail.com]

Hi,

Thanks for reply but can u tell me how is this possible if we use layer 3 switch.

Thanks

[glen.grant]

  If your connections between the switches are routed links then STP is irrelevant and is not run on those links . 

[rais]

Is stacking an option?

Thanks.

[pradyumnayadavgla@gmail.com]

Hi, He did not give me any option like Stacking. if we can do this using stacking than share answer... Thanks,

[rais · Accepted solution]

On Juniper EX switches you can use virtual-chassis to turn upto 10 switches into a single logical switch.  All switches connect to each other in a ring topology. No blocked ports and no STP required.

I believe Cisco stackwise+ is a similar solution. 

Also, you should be able to use vPC feature to achive the same with STP on.

Thanks.