[4500X] Convert standalone to VSS, what about old configuration?

[Clement BONNAL]

Hello,

I need to convert 2* 4500X from standalone to VSS, in a network production, and during business hours.

I didn't found any documentation, but I found the 6500 one, so I will use it and adapt.

But I have one question :

If I begin to convert first chassis, from my previous experience, it may keep config and reload in VSS mode.

But when I convert the 2nd one and reload in VSS mode, does it download its config from active (1st) chassis (and so it will not have any config as it was never provisionned on the first), or as it the first time that the VSS come up, the 2nd chassis will send its old config to the active and configure its ports from old config?

So second question:

Is there a difference if I begin conversion by the 1st or the 2nd chassis ?

Thank you so much,

[Reza Sharifi]

Hi,

I would not recommend changing from stand alone to VSS during business hours, unless down time is not an issue for you. This conversion should be done during a planed maintenance window as your config will change and therefore you would need sometimes to convert the old config to the new one. Once you convert to VSS and bring up the stand-by chassis, all config from the active chassis will be synced to the stand-by.  This will overwrite any config that existed on the chassis before conversation. I recommend you make a good copy of the existing config in notepad and once the chassis are converted, modify the config, copy and paste it to the VSS.

HTH 

[Clement BONNAL]

Hi Reza,

As it is an hospital, there is no non-business hours or planned maintenance.

I decide to migrate with following action plan :

- Reload chassis #1 in VSS Mode (no service disrupting as chassis #2 continue to work)

- Reload chassis #2 in VSS Mode (no service disrupting as VSS #1 is working on old STP config)

- Chassis #2 join VSS with all ports shutdown => Configure Po & Routing and keep it shutdown

- Configure Po & Routing on Core and Access switches, then activate ports on VSS #2

- Shutdown all VSS #1 ports, configure interfaces into Po and keep it shutdown

- Configure interfaces into Po on Core and Access switches, then activate ports on VSS #1

Is there anything I forget ?

Regards,

[Reza Sharifi]

Hi,

At what step are you planning to configure the VSL links and verify?

Also, at what point you are going to convert the existing ports to match the VSS?

For example, if port 1/5 from both existing switches were connected to an access switch, once VSS is configured, the same ports will be 1/1/5 and 2/1/5 and so at some pint you have to modify the old config to match the new one.

I understand this is a hospital and can't have any down time, but is there a way for you to test this in a lab environment before trying it in production.

HTH

[Clement BONNAL]

Hello,

I plan to configure VSL just before rebooting in VSS mode, as 6500 doc says. (I just wrote global actions in my last message)

Next, when sw1 reload in vss mode it will rename its ports but keeps config. So no impact on access switch.

However, after sw2 reload, it will lost its config and shut its ports. I check VSL at this time and I configure ports in Po and the mirror on access switches before enable it.

For sure I will test it before in lab.

Regards

[Reza Sharifi]

Yes, defiantly testing will help in figuring out the correct steps.

Good Luck 

[Clement BONNAL]

Hi,

Migration is done without any downtime.

However, the standby chassis did not shutdown its ports when joining VSS for the first time.

It had no impact because access uplink ports have strong config, but it could be bad if trunk negociation is active.

Regards

[Adnan Khan]

What were your steps to convert into VSS without downtime?