ICX6450 Stacking Question

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Hello,

I have 6 ICX 6450 in a stack. 3 on one floor and 3 on another floor. We're no longer leasing 1 of the floors and therefore consolidating everything. The 3 switches that need to be moved are acting as the active and standby switches with all others being members. What would be the best way to move these switches?

Should I make one of the switches NOT being moved the active switch and reload the stack before unplugging those switches to be moved? Or can I just unplug them and move them without doing anything? Not sure what happens to the stack when it loses both active and standby switches.

Any help will be greatly appreciated.

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Jonathan McHugh

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Posted 2 months ago

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Ben, Employee

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I would just make one of the switches that is not moving the master ahead of time by changing the priority:

conf t
stack unit <stack-unit-num>
priority 255

You could also assign a standby in the same way. 
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NETWizz

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I would echo what Ben mentioned and also recommend hitless-failover be enabled as well to prevent the whole stack from restarting when you make a topology change.
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Jonathan McHugh

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Thank you guys for the answers I really appreciate that.

So I could do
 
conf t
hitless-failover enable

Then run
conf t
stack unit <stack-unit-num>
priority 255

Then the stack doesn't have to be restarted? Would the current master switch restart after assigning a new master?
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NETWizz

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That I am not sure.  I would have to do a lab test to be sure, but at the moment I am hammered making firewall changes for another project.

Certainly, if you remove switches that are NOT the master or standby hitless-failover should allow just the moved switches to restart.

That said, I do not know if it will be a simple re-election for a master change or if that will result in a stack reload.  You would probably need three (3) or four (4) of those to build a stack and test.

From the sounds of it, you may need to do some stacking gymnastics and musical switches in that the definition merely says:

Hitless stacking failover provides automatic failover from the active controller to the standby controller without resetting any of the units in the stack and with sub-second or no packet loss to hitless stacking-supported services and protocols.


That would lead me to think you would have to do some numbering, so a desirable standby is elected first THEN failover from the active controller to that standby... and then change to another standby and wait for the re-election to finish.

***

This is the kind of stuff where I just build a lab or schedule downtime if I cannot be bothered.  It is also the type of stuff I do not guarantee will not cause an outage to management.
(Edited)
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Jonathan McHugh

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Man I do appreciate the help. I'll probably just stay late one night and set the new master and just reload the whole stack. I think they've been up for like 540 days anyway so probably wouldn't hurt to give them a reboot.

Good luck with all those firewall changes.
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Ben, Employee

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Hey Jonathan. You should not need to restart the stack at any point. Simply make sure you have hitless failover enabled and then you can change the priorities at will without reloads. "show stack" output will show you exactly what is happening in regards to master, standby, syncing protocols, etc. My advice would be to manually swap over active and standby prior to shutting down the units. 
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Jonathan McHugh

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That's what I'll do then. Enable hitless failover, then change my priorities. Thanks so much everyone!