Aruba CX VSF Auto-Stacking

VSF stacking

There are multiple ways to form a VSF stack on HPE Aruba Networking switches. One of these ways is to use the "auto-stacking" feature. This feature allows us to form a stack with minimal user intervention and generally simplifies the process. This can be done on any switch that supports VSF, so 6200 series and 6300 series switches. As a general reminder, you can stack any model with one another within the same series (exception: 6200 12-ports) and CANNOT stack models from different series with each other.

There are also a few caveats to be aware of, so read on to see how it's done!

The physical setup

A couple of things need to be considered when using auto-stacking. The first is which ports to use. Auto-stacking uses predetermined ports to discover and build the VSF stack. Those ports are the "inner" SFP+/SFP56 ports of your switches, so ports 25 and 26 on 24-port models and ports 49-50 on 48-port models.

The second caveat is the "direction" in which you add new members to the stack. Any new member must be cabled going from their lower numbered port to the higher numbered port on the existing (or future) stack member.

Here's a picture of the stack I'm building using three 6300 switches:

Take note of the use of the inner SFP56 ports as well as the direction of the stack. The top switch is going to be the conductor of the stack and all other switches are going "up" (to the higher numbered port). I didn't have enough cables to complete the ring, but in a real-world deployment you should do so.

Launching auto-stacking

We can use different methods to launch auto-stacking, the main ones being through a CLI command or by using the "LED mode" button (Stk LED) on the conductor. Since I'm going to be showing the state of the stack as it sets itself up, I'll be using the CLI command.

At this point, all my switches are in a factory-default state (mandatory!), cabled using DACs and powered on.

On my top switch (future conductor), here is the VSF state before I start the auto-stacking process:

6300# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary :

Topology : Standalone

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

Now let's launch auto-stacking using the "vsf start-auto-stacking" command:

6300(config)# vsf start-auto-stacking 

This will configure links and secondary on conductor

Do you want to continue (y/n)? y

6300(config)#

This is all I'll be entering in the CLI. The command will configure the interfaces used for the VSF links using the predetermined assignments and will also assign member IDs along with a standby conductor (member 2)

This is the state of VSF after entering the command and waiting about a minute:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Standalone

Status : Active Fragment

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 JL666A Not Present

So my second switch was detected, added to the stack and rebooted.

After the second switch comes back up, the VSF state shows an OS version mismatch:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : Active Fragment

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A OS Version Mismatch

The conductor sends the OS image to the new member, the member updates itself and reboots:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Standalone

Status : Active Fragment

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 JL666A Not Present

The second member comes back online and becomes the standby conductor:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : Active Fragment

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby Booting

Once the second member is fully booted, the process continues where the stack discovers the third switch, reboots it, conductor sees an OS mismatch, conductor updates it and the new switch finally joins the stack.

Reboot third switch:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby

3 JL666A Not Present

Version mismatch for third switch:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby

3 0c:97:5f:9c:0b:40 JL666A OS Version Mismatch

Update third switch and reboot again:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby

3 JL666A Not Present

Third switch coming back online:

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby

3 0c:97:5f:9c:0b:40 JL666A Member Booting

The stack is now up and running with the three switches. This process would continue until there are no more switches to add to the stack, up to a maximum of 8 for 6200 series switches and 10 for 6300 series switches.

6300(config)# show vsf

Force Autojoin : Disabled

Autojoin Eligibility Status: Not Eligible

MAC Address : 38:10:f0:4d:f7:80

Egress Shape Rate : None

Secondary : 2

Topology : Chain

Status : No Split

Split Detection Method : None

Mbr Mac Address type Status

--- ------------------- -------------- ---------------

1 38:10:f0:4d:f7:80 JL660A Conductor

2 14:ab:ec:cd:8f:c0 JL666A Standby

3 0c:97:5f:9c:0b:40 JL666A Member

You can also confirm everything is cabled as expected by displaying the VSF topology:

6300(config)# show vsf topology

Standby Conductor

+-------+ +-------+ +-------+

| 3 |1==2| 2 |1==1| 1 |

+-------+ +-------+ +-------+

As mentioned in the beginning, this could also have been done by pressing the LED mode button until the "Stk" LED lights up. This method follows the same process (if everything is cabled correctly) and would enable you to build the stack with no console connection to the conductor switch.

Ben's brain overflow

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