Cisco Stackwise


(Rene Molenaar) #1

This topic is to discuss the following lesson:


(ahmad a) #2

very nice and perfect article, there is one little edit ( what is the number of switches that can be added to the stack ? )

thanks


(Rene Molenaar) #3

Thank you Adhmad. Normally up to 9 switches can be stacked.


(Pham H) #4

HI, I have a question : what is the different between stackwise and VSS. Can you explain please. Sorry about my English(alittle). Thanks so much .


(Rene Molenaar) #5

Hi Pham,

Stackwise and VSS are both techniques to create a single virtual switch out of multiple physical switches. Stackwise is used on the Cisco Catalyst 3750 (and some others like the 2960-S) switches while VSS is used on the 4500 and 6500.

Rene


(Pankaj J) #6

Hi Rene

Hope u r doing well.

Want to know that do the hardware configuration and software configuration( Cisco 3750) has to same in switches we using in stack.


(Rene Molenaar) #7

Hi Pankaj,

You should use the same platform and same IOS versions yes.

Rene


(Scott L) #8

Hi Rene,

“If the master fails, another member will become the new member.”

You mean Master?! :slight_smile:

Regards,

Scott


(Rene Molenaar) #9

Oops…just fixed it :slight_smile: Thanks for letting me know Scott!


(Ashok L) #10

Hi Rene,
I have couple of questions here…
Consider a stack of 2 switches. Do We need to enable spanning tree on the stack for connecting other switches on this stack, in a redundant manner ?
Also How does the IOS upgrade happen on the member switches in stack? Would the upgrade on master take care the member switches too?


(sepideh a) #11

Hi
What is difference between stack and VSS? Both create one virtual switch which is combination of 2 or several switches!!!


(Rene Molenaar) #12

Hi Sepideh,

Both have similarities. VSS is used on the 4500 and 6500 switches and can be used to combine two switches into a single virtual switch.

Stackwise is used on the smaller switches like the 3750.

Rene


(Rene Molenaar) #13

Hi Ashok,

You don’t need STP for the connections between the switches in the stack, the stack is seen as one “logical” switch.

If you want to upgrade the IOS image then you should copy the image to the flash memory of all your switches, then configure the master switch to boot the new image and reload the switches. Cisco has a good document with some examples:

Rene


(Gaganpal D) #14

Hello Rene,

why we need to configure in switch 1 #switch 2 renumber 1 ?

what is mean by Provision state ?

when we are using “sh switch command” instead of showing" ready" it’s showing as" provision" could you please help me to resolve the issues ?

 

 

 

 


(Ronie S) #15

Hi Rene,

Thank you for this tutorial . I would like to know more on how to do the provisioning of the stack members and what are the proper procedures for removing stack. And also the differences (speeds, source stripping and destination stripping,etc…) between Stackwise and Stackwise plus.

 

Thank you.

 

Best Regards,

Ronie


(Rene Molenaar) #16

Hmm I think it shows up as “provision” when the switch isn’t successfully added to the stack or when the stack cable is disconnected.

Renumbering can be used to change the interface numbers. Depending on the stack number you will have interface numbers like fa1/0/1 or fa2/0/1 or something.

@Ronie Cisco has a pretty good document that explains the differences between these:

 


(Thomas K) #17

Rene,

Hi. I think that there exact order of the stack member election might not be correct when compared to what is outlined at URL below.

 

 

Thomas


(sze jie k) #18

Hi Rene,

Can you advise if the following behaviour is normal

T1) 2 x 2960x stacked - show switch reflect 1 master and 1 member.

T2) stack cables are removed from both switches and a reboot is done

T3) both switches reflected themselves as Master and the other as member

T4) plug back stacking cables, but no re-election occur.

Both switch remain “split brain” thinking itself as the Master, even if the stack cable is reconnected back.

 

Is this behaviour normal or a bug ?
Is there anyway to force a re-election without rebooting the switch ?

 

Regards,
Alan


(sze jie k) #19

Hi Rene,

To add on to the previous post, i would like to highlight that

a) when the stacking cable is added back to connect the 2 switches together, each switch still think itself as Master and show the other switch as Member.
Each of the switch also show the other Member switch’s status as “Provisioned” instead of “Ready” - why doesn’t the status become “Ready” ?

in Switch A -> Switch A (Master/Ready), B (Member/Provisioned)
in Switch B -> Switch B (Master/Ready), A (Member/Provisioned)

 

b) I rebooted one of the switch (Switch B), and when it is backup, no election take place also. The status remain the same as above.
It is only when i rebooted both switch together, then the re-election process begin.

 

Why ? Is this normal ? Does that mean everything my stack cable is down, i would have to restart the whole stack ?!

 

Regards,
Alan


(Rene Molenaar) #20

Hi Alan,

Hmm I think this is normal. When there is no cable, both switches will elect themselves as the master. There is no preemption so once a switch is master, it will remain master. After connecting the cable you would expect a re-election but I don’t think this occurs.

If you keep the cable connected and reboot the switches, then everything works fine?

Rene