SG500X stacking

[calzone]

We have several SG500X running as access switches in our office. Now one of them has to be expanded because we need more ports.

I basically know how to build a stack with new SG500x, but though I double-checked the adminguide and read tons of discussions, I haven't found an answer to a quite simple question: what happens to the running config of an existing single switch if I just plug in the stacking cable and connect a brand new second switch to build a stack? Do I have to rewrite the whole config or will they just automagically stack, optionally with a reboot?

Stacking mode on the running switch is set to native (default setting), so I don't have to change it. This was the only issue I found about the risk of losing the running config.

Maybe the answer is too simple to write it down, but could you please do it for me?

[Deepak Kumar · Accepted solution]

Below I list what you should know and understand before stacking.

• A standalone switch is a switch stack with one stack member that also operates as the stack master.
• Make sure that you power off the switches that you add to or remove from the switch stack. I have not found a clear reason for this, perhaps it’s to prevent any corruption of the stack. Obviously, you can add or remove a switch during stack production.
• A new, out-of-the-box switch (one that has not joined a switch stack or has not been manually assigned a stack member number) ships with a default stack member number of 1. When it joins a switch stack, its default stack member number changes to the lowest available member number in the stack.
• If you manually change the stack member number, it only takes effect when you reset that specific member switch.
• The configuration that you create on the switch stack is called the provisioned configuration.
• The switch that is added to the switch stack and that receives this configuration is called the provisioned switch.

what happens to the running config of an existing single switch if I just plug in the stacking cable and connect a brand new second switch to build a stack?

It is recommended to reset the switch before add to stacking and reconfigure some settings as a Provising number and Priority etc. But in most of the cases existing single switch configuration has rewritten with the provisioned configuration. But It not recommended.

Why not? I didn't get a clear answer but I am thinking that due to some human error or power error if Master switch will restart and your newly added switch is having High Priority and stack member number then you will lose the provisioned configuration.

Regards,

Deepak Kumar

Deepak Kumar 

[calzone]

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@Deepak Kumar wrote:

...

• A standalone switch is a switch stack with one stack member that also operates as the stack master.

...

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This is exactly what I thought this morning when "suddenly and unexpected" the expansion became so urgent that it had to be done immediately...

So I powered on the new switch just to check the firmware version. It was older than the version on the existing one -- ok, power off. Backup is up-to-date -- let's go for it!

SSH login to the existing switch to watch console messages, connecting the new (powered off!) switch via stacking cable. Powering on the new one - it was registered as unit2, synced its firmware from the master and rebooted once - done! The whole job was finished in about 15 min without downtime of the (still running) master, quite easy :-)