2960-X Switch Stacking

[bartosikr1]

Hello -

I currently have a few closets that have 2-3 standalone 2960-Xs in them which we would like to Stack.

A few questions -

1 - Do all the Stack Members have to running the same IOS Ver?

2 - Can these be done "live" or is downtime necessary? Guessing downtime is needed to backup current configs and then paste to new stack?

3 - When you cable all 3 switches, basically do just console cable connect to one of the stack members and paste the config backup made from the  standalone members and then your done?

Any help, guides or direction is appreciated.

Thanks,

[Alexey Prilutskiy · Accepted solution]

Here is the great article about stacking of C2960-X - http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-2960-x-series-switches/white_paper_c11-728327.html

In short:

1. Yes. also there is the table of allowed IOS feature sets combinations in the article;

2. Yes, but every new stack member will be rebooted after adding to the stack;

3. Better to configure first switch with that config and make it stack master with stack priority (or it will be the master if has biggest uptime). Then you will add more switches to the stack and config will be copied on them automatically;

[Mark Malone]

Hi stack modules are hot swappable so you should be able to do this without any downtime

best to have the ios to match exactly if possible but you can stack with different ios but versions should match or you will have issues

Take a look at these may help, be careful there are per-requistites to stop the whole stack reloading when adding the members you need to have a switch set as the active(master) if your trying to avoid downtime

Switch Stack Membership

A standalone switch is a switch stack with one stack member that also operates as the active switch. You can connect one standalone switch to another to create a switch stack containing two stack members, with one of them as the active switch. You can connect standalone switches to an existing switch stack to increase the stack membership.

Changes to Switch Stack Membership

If you replace a stack member with an identical model, the new switch functions with exactly the same configuration as the replaced switch, assuming that the new switch (referred to as the provisioned switch) is using the same member number as the replaced switch.

The operation of the switch stack continues uninterrupted during membership changes unless you remove the active switch or you add powered-on standalone switches or switch stacks.

• Adding powered-on switches (merging) causes all switches to reload and elect a new active switch from among themselves. The newly elected active switch retains its role and configuration. All other switches retain their stack member numbers and use the stack configuration of the newly elected active switch.

• Removing powered-on stack members causes the switch stack to divide (partition) into two or more switch stacks, each with the same configuration. This can cause:

  • An IP address conflict in your network. If you want the switch stacks to remain separate, change the IP address or addresses of the newly created switch stacks.

  • A MAC address conflict between two members in the stack. You can use the stack-mac update force command to resolve the conflict.

If a newly created switch stack does not have an active switch or standby switch, the switch stack will reload and elect a new active switch.

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/stack_manager/configuration_guide/b_stck_152ex_2960-x_cg/b_stck_152ex_2960-x_cg_chapter_010.html

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_53_se/configuration/guide/2960scg/swstack.html#wp1177470

http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-2960-series-switches/white_paper_c11-578928.html

[bartosikr1]

Thanks Mark!

So if I have a few WS-C2960S-48FPS-L' running IOS 15.0(1)SE2 and the new ones come with 15.0.2-SE8(MD); we should be Ok?

Thanks, 

[Mark Malone · Accepted solution]

Yes you should be good with them same major number 15 and same minor 0 there compatible

[bartosikr1]

Thank You Mark!

[bartosikr1]

Hi Mark - Would you able to very the config process as I understand it?

1- Backup the config from Member #1 and Member #2.

2 - Shutdown Member #2

3- Load the config for both Members onto Member #1

4 - Install Modules and Cable Members #1, #2 and #3

5 - Power On Members #2 and #3

6 - Config from Member #1 should replicate to #2 and #3

Done

[Mark Malone]

Before adding anything make 1 of the switches the active/master switch if you dont when you add  2 switches together they will both reload and talk to each other until they have decided who master is.This will obviously cause downtime which your trying to avoid

If you set 1 as master only the slave reboots as its added to the master ,the config will be on the master and when the slave gets added and reboots you just end up with all its extra ports in your config when you console in and then its the same for each switch as there added

Take a copy of each config before adding anything as you said above , once the switch joins the stack you can transfer over its port config and whatever else is required , the master will still have its own original config

Just add 1 at a time as then if there's an issue you can easily roll back, you cant add the config until the switch has fully joined the master 

https://www.youtube.com/watch?v=mFh_j3r97LA

https://www.youtube.com/watch?v=Z-fXAgKdV14

[bartosikr1]

Great info!

So the above is the process for creating a Stack of 2 Members? Master would be the already existing switch but to be safe we would change the Priority to 15? Add modules to both switches, cable them, and we are good?

Modules can be installed "live"?

It works the same for adding a 4th Member to an already created Stack of 3? A Master would have already been configured but to be sure, check that Priority is 15? Then you would just power down the Stack, re-cable for a fourth member, boot up and the config from Master get deployed to the other 3 Members?

Sorry just need to get it straight in my head.

Thanks!

[Mark Malone]

Yes all switches from what i remember have a default priority of 2 out of the box , set it as 15 it will be the master always as its the highest priority,flexstack module on a  2960 is hot swappable can be done live

once you have added 1 switch to the stack its the same process for each other member you dont need to power down the whole stack each slave switch reboots as it joins the stack and adds itself automatically to the master you will just see inyour  show run you have more ports(switch 2s ports and so on as you add them) the master should stay up

i would review the doc i posted earlier stack manager 2960 before going at it, its got some good pointers and examples in it that will help

hope you get it working without too much downtime , i would prepare a maintenance window anyway things can go wrong and sometimes the stack will flip even if you do things right that's from experience

[Mark Malone]

Important from that doc

[bartosikr1]

Thanks Mark! You have helped me greatly!

[bartosikr1]

Thanks Alexey!

For #3 - Are you saying that I would

1- Backup the config from Member #1 and Member #2.

2 - Shutdown Member #2

3- Load the config for both Members onto Member #1

4 - Install Modules and Cable Members #1, #2 and #3

5 - Power On Members #2 and #3

6 - Config from Member #1 should replicate to #2 and #3

Done