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Static Numbering or Manual Unit ID Assignment on the SG550XG and SG350XG Switches

Table of Contents


After setting up a stack topology, each unit in a stack is assigned a unique ID either manually or automatically. For information on Automatic ID assignment, please refer to the Auto-Numbering article.

The objective of this document is to show you how to manually set stack unit IDs for the SG350XG or SG550XG series switches. For a full demonstration of static numbering, please view the video below:

Applicable Devices

  • SG350XG

  • SG550XG

Software Version

  • v2.1.0.46

Static Numbering or Manual Unit ID Assignment

With static numbering, you can manually define the unit ID of each device, allowing you to determine the initial master, backup, and slave units.

Initial Set-Up

For this demonstration, we will connect four SG550XG Switches in a chain topology. For detailed information on how to set up a chain topology, please refer to Ring and Chain Topologies.

Step 1. Once you have physically connected your devices in a chain topology, log into the web configuration utility for each switch and navigate to Administration > Stack Management to configure the stack ports appropriately.

Step 2. In the Unit ID After Reset drop-down list, choose an integer from 1 to 8 to uniquely assign a unit ID for each switch.

Note: You will need to assign a unit ID of 1 to one of the switches to designate a stack master for a functional stack.

Step 3. Click Apply and Reboot to save changes for each switch. A confirmation window will open asking if you would like to continue. Click OK and your device will reboot.

Note: After changes are applied and each device resets, you can observe the successful ID assignment by looking at the Stack ID LED indicator on each switch. If you assigned an ID greater than 4, multiple LED indicators will light up and their sum will denote the unit ID of the switch.

Modifying Unit ID Assignment

Step 1. After all switches finish rebooting and become a stack, log into the stack master’s web configuration utility and navigate to Administration > Stack Management.

The Stack Topology View section shows your current stack topology and its static numbering configuration. You can select each individual switch and edit its unit ID.

Step 2 (optional). Select the switch you want to modify. In the Unit ID After Reset drop-down list, choose a new integer to assign as the unit ID for the switch.  

Note: Changing the unit ID of one switch may require changing the unit ID of another switch in the stack to avoid duplicate numbering.

Step 3 (optional). Click Apply and Reboot to save any changes you made to your static numbering configuration. The updated numbering and stack configuration will appear in the Stack Management page after the devices reset.


Static numbering gives you control in configuring your stack by allowing you to choose the unit IDs for each switch. As a result, you can easily modify the stack topology and designate which units are the stack’s master, backup and slaves. After setting up your stack physically, you can access each unit’s stack management page and assign its unique unit ID number.