In the pfSense ecosystem, "serial number" can refer to physical hardware identification, software-linked identifiers for support, or even cryptographic certificate metadata. 1. Hardware Identification
For official Netgate hardware, the serial number is a unique physical identifier used to track warranties and support eligibility.
Location in WebGUI: Often displayed in a dashboard widget if the hardware is recognized. If the hardware is a generic "white box" or a custom build, the system may show a Host UUID instead.
Command Line Retrieval: You can attempt to find the serial number using the dmidecode or kenv commands via the Diagnostics > Command Prompt or an SSH/console session. 2. Software & Support (Netgate ID/Serial)
In recent versions, such as pfSense Plus, the serial number (or Netgate ID) is essential for software lifecycle management.
Netgate ID: This unique string is used to identify your specific instance for the purpose of pfSense Plus firmware requests and software updates. pfsense serial number
Support Tickets: Netgate support staff use this identifier to verify your device's original order, warranty status, and whether support services are active for that specific unit. 3. Serial Console Access
"Serial" also refers to the Serial Console Port used for emergency management and initial configuration. Show serial number in webgui? - Netgate Forum
A "full guide" for pfSense serial numbers covers several different topics depending on what you are trying to achieve. Are you trying to find the serial number of your hardware? Are you trying to change the serial number in the configuration (common with China-imported network cards)? Or are you looking to validate a Netgate appliance license?
Here is the comprehensive guide covering all aspects of pfSense Serial Numbers.
If you have administrative access to the web interface: In the pfSense ecosystem, "serial number" can refer
Q1: Can I change my pfSense serial number? A: On Netgate hardware, no—it is burned into the secure element. On generic hardware, you can change the DMI/SMBIOS data, but it will not grant you a valid pfSense Plus license.
Q2: I lost my Netgate device sticker. Can I recover the serial?
A: Yes. Log into the WebGUI (System > General Setup) or use dmidecode -s system-serial-number via SSH. If you cannot boot, the serial is sometimes printed on the PCB inside the device (warranty void if opened).
Q3: Does pfSense CE send my motherboard serial to Netgate? A: No. pfSense CE is completely open-source and does not phone home. Only pfSense Plus and AutoConfigBackup services transmit the serial (over encrypted TLS).
Q4: My serial number shows "0123456789" – is that real?
A: That is a placeholder from a generic BIOS. Real Netgate serials are alphanumeric and model-specific (e.g., 6100a1y2305001).
pfSsh.php
print_r(get_single_sysctl('system.serial'));
This returns the raw serial string for scripting purposes. Method B: The WebGUI (Dashboard) If you have
Let’s jump into the story of Alex, a junior network admin at a regional library system.
One Tuesday morning, their primary SG-3100 firewall began rebooting every 20 minutes. The library’s patron internet died. Alex panicked. The device was out of warranty, but he had purchased a pfSense TAC Support subscription tied to the device’s serial number.
He opened a ticket with Netgate Support, attaching the output of cat /etc/version. Within minutes, support identified the serial as part of a batch with known eMMC wear issues. Because the serial number was on file, they sent a replacement RMA unit overnight—no questions asked.
But here’s the magic: The new unit’s serial number was different. Alex plugged it in, booted to pfSense, and selected “Restore from AutoConfig Backup”. The system asked: Enter your previous serial number.
He typed SG3100W123456789. The pfSense cloud service (Netgate’s AutoConfig Backup) downloaded the exact configuration—firewall rules, VLANs, OpenVPN certs—and applied it to the new serial number. In 10 minutes, the library was back online.