Number: Pfsense Serial

⚠️ Warning: Do not change the serial number on Netgate hardware. It voids support and ACB functionality.

For pfSense CE (software only):

If SNMP is enabled, the serial is often found in: NET-SNMP-AGENT-MIB::nsAssetID

Or via a standard OID walk:

snmpwalk -v2c -c public pfSense-IP 1.3.6.1.4.1.8072.1.3.2

One advanced feature that relies on the pfSense serial number is Automatic Configuration Backups (ACB) – also known as "AutoConfigBackup." pfsense serial number

Netgate offers a free cloud backup service for pfSense configurations. Here is how the serial number is used:

Why this is powerful: If your firewall dies, you can:

Warning: Restoring a config from a different serial number requires the system_reset_uniqueid() trick mentioned above, or you will face licensing conflicts.

For DevOps and large-scale deployments, you can pull the serial number programmatically. ⚠️ Warning : Do not change the serial

If you cannot access the GUI, you can retrieve the serial via the console or SSH.

For Netgate Appliances (Hardware Serial): Connect to the console (Serial or SSH) and select option 12 (Developer Shell) or 8 (Shell). Run the following command to query the hardware BIOS:

dmidecode -s system-serial-number

Alternatively, on newer Netgate hardware, run:

sysctl -a | grep netgate

(This often reveals the specific Netgate device ID and hardware serial). For pfSense CE (software only): If SNMP is

For pfSense Plus System ID: From the Shell (Option 8):

cat /etc/pfsense-serial

If you are using an official Netgate appliance (SG-2100, SG-5100, etc.):

In pfSense software, a serial number is a unique identifier automatically generated during installation. It is not a license key or hardware ID (unless running on official Netgate hardware, where the device’s serial number may be used).