What is the “module provision switch” command?

[JustTakeTheFirstStep]

I do not understand the meaning of the command in C4507.

What does Provision mean?

module provision switch 1
chassis-type 68 base-mac 1C6A.7A0A.B900
slot 1 slot-type 399 base-mac 7C0E.CE6C.7D70
slot 3 slot-type 404 base-mac 1C6A.7A0A.B900
slot 5 slot-type 387 base-mac 7C0E.CEB1.EA7C
slot 7 slot-type 383 base-mac B838.6118.3678
!
module provision switch 2
chassis-type 68 base-mac 1C6A.7A0A.B9C0
slot 1 slot-type 399 base-mac FC5B.3906.4154
slot 3 slot-type 404 base-mac 1C6A.7A0A.B9C0
slot 5 slot-type 387 base-mac 7C0E.CEB1.EA4C
slot 7 slot-type 383 base-mac E4C7.22FA.A404

[M02@rt37]

Hello @JustTakeTheFirstStep 

The "provision" command is used to configure the hardware characteristics of the switch modules. This command allows you to specify the type and characteristics of the modules installed in the switch chassis.

[pieterh]

this means two switches are connected and configure as a single unit
this has several advantages, 
- seen from management view, you only access a "single" switch to configure both members
- seen from network view, you can configure redundant connections to multiple physical switches

Catalyst 4500 Series Switch Software Configuration Guide, IOS XE 3.8.xE and IOS 15.2(4)Ex - Configuring Virtual Switching Systems [Cisco Catalyst 4500 Series Switches] - Cisco

[JustTakeTheFirstStep]

@pieterh M02@rt37 

Two 4507 switches are aggregated with VSS.

As you know, it is possible to configure VSS without using the module provision switch command.

I would like to know the advantages of using the module provision switch command.

[M02@rt37 · Accepted solution]

@JustTakeTheFirstStep 

With module provision switch, you can specify the expected module types and their slot numbers in advance.

This provides a form of validation, ensuring that the modules installed in the chassis match the expected configuration. If there's a mismatch, it can be detected during the provisioning process.

When you use module provision switch, it helps in ensuring that the slot numbers are consistent across both switches in the VSS. This consistency simplifies the configuration and management of the VSS, as you can expect the same slot numbers on both physical switches.

If a module needs to be replaced or if you're adding new modules, having a predefined configuration can make the process smoother. The new module can be inserted into the correct slot according to the provisioned configuration, and the VSS can be updated accordingly.

[M02@rt37 · Accepted solution]

Hello @JustTakeTheFirstStep 

While VSS can be configured without using this command, there are advantages to explicitly provisioning the switches.

Using the provision swith command help ensure that each switch in the VSS pair has a predetermined role (either primary or secondary). This makes the VSS behavior more predictable during normal operation and also during maintenance or upgrades.

Also, without explicit provisioning, the system might determine the primary and secondary roles automatically, which could lead to unexpected behavior during network events or failures.