topic RE: Adding 3rd switch to stack in ExtremeSwitching (EXOS/Switch Engine)

Adding 3rd switch to stack

Gaurav_Madan — Fri, 20 May 2016 09:38:00 GMT

HI All

I have a LIVE network having 2 switches already stacked as follows :

#show stacking
Stack Topology is a Ring
Active Topology is a Ring
Node MAC Address Slot Stack State Role Flags
------------------ ---- ----------- ------- ---
*00:04:96:35:e5:0b 1 Active Master CA-
00:04:96:51:fd:60 2 Active Backup CA-

I need to add a 3rd switch to this stack in a maintenance window

1) I have made sure that version is compatible
2) I have made sure license level is compatible.

Is the following process fine ? Need some confirmation :
***************************************************************
1) Power down new switch and cable it up in the stack.
2) Power the new switch back up.
3) On the existing stack verify the new switch is being seen by the current stack
(The command below will display the new switches MAC and show that stacking is disabled):
show stacking

4) On the existing stack, type the following commands:
a. configure stacking node-address slot 3
b. synchronize stacking node-address
c. enable stacking node-address
d. reboot node-address

Question # 1 : If above steps are true ; does this mean we will not power down the existing switch stack (slot 1 and 2 ) ?
Question # 2 : If above steps are true ; does that mean that existing config (1:1 -> 1:50 and 2:1 ->2:50) will remain intact and we will additionally see
ports number 3:1 ->3:50 ?
Question # 3 : Hence does that mean that we will be able to do everything through console plugged in existing master switch (slot 1 console in my case) ?

Please guide on the steps to be followed as we will have limited time to do this activity

RE: Adding 3rd switch to stack

Ron_Huygens — Fri, 20 May 2016 10:39:00 GMT

Hi Gaurav,

It depend on the model, but in general the answer to all of your questions is yes.
If this is a summit X670v you need to enable stacking support on the new node first.

RE: Adding 3rd switch to stack

Gaurav_Madan — Fri, 20 May 2016 11:02:00 GMT

These are X450a-48t

RE: Adding 3rd switch to stack

Ron_Huygens — Fri, 20 May 2016 12:55:00 GMT

Then you are good with the guidelines above

RE: Adding 3rd switch to stack

Gaurav_Madan — Fri, 20 May 2016 16:39:00 GMT

Thanks .. my only confusion in this case is :

At start of activity ; I will remove the stack cables in existing slot 1 and slot 2 ( as i need to re-arrange them to accomodate slot 3 as well )

earlier stacking is as follows :
SLOT 1
stack-port1 \ /
\ / stack port 2
SLOT 2

I will re-cable it as follows :

SLOT1 --------
/ |
/ |
SLOT2 |
/ |
/ |
SLOT3-------

As soon as I do this ; my slot 2 will also come out of stack . Now each of these 3 will be independent master in themselves

Hence I will be required to do following by logging in console of switch 1

a. configure stacking node-address slot 2
b. synchronize stacking node-address
c. enable stacking node-address
put priority of 14 for slot 2

a. configure stacking node-address slot 3
b. synchronize stacking node-address
c. enable stacking node-address
put priority of 13 for slot 3

Finally reboot the stack completely.

PLease confirm

RE: Adding 3rd switch to stack

Bill_Handler — Fri, 20 May 2016 17:21:00 GMT

If you have a closed loop, and it looks like you do, unplug the stacking cable from stacking port 1 on switch 1 (the other end should go into stacking port 2 on switch 2) and plug that into stacking port 1 on switch 3. At this point you should still have a stacking cable going between switch 1 & 2, so switch 2 will not come out of the stack.

Then you should be able to see switch 3 from the console of switch 1 (manager). When you see it there, you can run the stacking commands for switch 3.

You also should have a stacking cable to connect switch 3 (stacking port 2) to switch 1 (stacking port 1). We usually connect that cable after we have the stack up and running.

RE: Adding 3rd switch to stack

Darren_Saliva — Mon, 23 May 2016 17:20:00 GMT

you should also make sure that the same partition is used.

RE: Adding 3rd switch to stack

Chris_H — Tue, 24 May 2016 14:41:00 GMT

it is recommended to have slot 1 stack-port 1 go to slot 2 - stack port 2, then slot 2 - stack-port 1 go to slot 3 - stack-port 2.. this way you can connect slot 3 port 1 back to slot 1 stack-port 2.

it is not necessary to isolate slot 2 as bill already mentioned, just leave one link between slot 1 and slot 2 active and the existing stack will keep on working