The auto-numbering stacking mechanism is used to automatically assign each unit with a specific and unique stack unit ID based on the device MAC address. This is useful for a seamless integration of your SG550XG or SG350XG in a stack without the need to manually set the unit ID number of each stack.
If you are unfamiliar with terms in this document, check out Cisco Business: Glossary of New Terms.
The objective of this document is to show you how to configure your devices for auto-numbering.
For a full length demonstration of Auto Numbering, please view the video below:
Auto-numbering is used to automatically assign each unit with a specific stack unit ID based on the device's MAC address. When connecting four SG550XG switches in a stack topology, we can make two observations: these devices converge onto a single stack automatically, and each device will be automatically numbered.
Note: Auto-numbering works in the same manner for a stack of SG350XG switches as it does for a stack of SG550XG switches.
There are two types of stacking topologies that can be used with this series of switches: ring and chain. In this tutorial, we will be using a ring topology.
In a ring topology, all the switches are connected to each other in a closed loop. Each unit is connected to two other components on either side and communicates with these two adjacent neighbors. The benefit of using a ring topology is that if a connection in the stack fails, the stack will remain active.
Step 1. Log in to the web configuration utility, then click Administration > Stack Management. On this page, you can view what stack topology you currently have, and see which unit is the stack primary.
Step 2. On the GUI, click on a port to designate it as a stack port. A stack port is used by the switch to communicate with other units in the stack. A minimum of 2 stack ports must be selected, but note that any port on the switch can become a stack port.
Note: Make sure that the Unit ID After Reset field is set to Auto.
Step 3. Click Apply and Reboot to save your changes. Repeat this process for every other switch in your topology.
The auto numbering algorithm sets the devices with the lowest MAC address to the lowest unit number, which is unit 1. You can see the results of this algorithm in the Stack Management page, once your stack has been configured. On this page, you can select a switch in the topology to see its unit ID.
You can also change the topology of the stack without rebooting; if you rearrange the cables of the stack, the GUI will detect any changes made and update accordingly.
The auto-numbering feature is an easy way to set up your network topology and automatically assign switches in a stack. You can also use the web configuration utility to monitor the status of your stack, and see what topology the stack is currently in.