What causes start pxe over ipv4

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Last updated: April 4, 2026

Quick Answer: PXE (Preboot Execution Environment) over IPv4 is typically initiated when a computer's BIOS/UEFI is configured to boot from the network. This often occurs due to incorrect boot order settings, a temporary network issue, or specific network configurations designed for network booting.

Key Facts

PXE allows computers to boot from a network server before loading an operating system from local storage.
It's commonly used for operating system deployment, diagnostics, and diskless workstations.
PXE booting requires a DHCP server to assign an IP address and provide boot server information.
The process involves the client broadcasting a DHCP request, receiving an IP and boot file location, and then downloading the boot file.
Common error messages include 'PXE-E53: No network interface found' or 'PXE-M0F: Exiting Intel Boot Agent.'

What is PXE Booting?

PXE, or Preboot Execution Environment, is a standardized network protocol that allows a computer to boot from a network interface card (NIC) before loading an operating system from local storage. Essentially, it enables a computer to start up and load its initial boot instructions from a server on the network, rather than from its internal hard drive or SSD. This technology is particularly useful in enterprise environments for deploying operating systems, performing system diagnostics, or supporting diskless workstations.

How PXE Works Over IPv4

When a computer is configured to boot using PXE, its firmware (BIOS or UEFI) initializes the network card. The network card then broadcasts a DHCP (Dynamic Host Configuration Protocol) request over the network, specifically looking for a DHCP server. This request is made using IPv4 if the network is configured for it.

The DHCP server, if properly configured to support PXE, will respond to this request. The response includes not only an IP address for the client computer but also crucial information about the network boot server. This information typically includes the IP address of the TFTP (Trivial File Transfer Protocol) server and the name of the boot file that the client should download. TFTP is a simple protocol often used for transferring small files, which is ideal for the initial stages of booting.

Once the client receives this information, it uses TFTP to download the specified boot file from the TFTP server. This boot file contains the initial instructions for the next stage of the boot process, which might involve loading a bootloader, an operating system installer, or a diagnostic tool.

Common Causes for Unintended PXE Booting Over IPv4

Several factors can lead to a computer attempting to PXE boot when it's not intended:

Incorrect Boot Order: This is the most frequent culprit. The computer's BIOS/UEFI settings dictate the order in which it attempts to boot from different devices (e.g., hard drive, USB, network). If 'Network Boot' or 'PXE Boot' is set as the first or a high-priority boot option, the system will attempt to boot from the network before checking the internal drive. This can happen after a system update, a BIOS reset, or if the user inadvertently changed the setting.
Network Configuration Issues: Sometimes, network infrastructure can inadvertently trigger PXE. If a DHCP server on the network is misconfigured or if there are rogue DHCP servers, they might offer PXE boot information to clients. This is less common but possible in complex network setups.
Hardware Initialization: In rare cases, the network card's firmware or its initialization process during POST (Power-On Self-Test) might incorrectly signal the system to attempt a PXE boot.
Specific Network Environments: In corporate or educational settings, PXE booting is a standard method for deploying or repairing operating systems. If a computer is connected to such a network, and its boot order is set to prioritize network booting, it will naturally attempt a PXE boot.
Corrupted Boot Sector on Local Drive: Although less direct, if the primary boot device (like a hard drive) has a corrupted boot sector, the system might fail to find a valid bootloader and then fall back to other boot options, potentially including PXE if it's prioritized.

Troubleshooting and Prevention

If you're encountering unintended PXE boot prompts, the primary solution is to access your computer's BIOS/UEFI settings. During startup, you'll typically see a prompt to press a specific key (like F2, F10, F12, DEL, or ESC) to enter setup. Once in the BIOS/UEFI:

Locate the Boot Settings: Navigate to the section related to 'Boot Order', 'Boot Priority', or 'Boot Sequence'.
Adjust Boot Order: Ensure that your primary storage device (e.g., 'Hard Drive', 'SSD', 'Windows Boot Manager') is listed as the first boot option. Move 'Network Boot' or 'PXE Boot' to a lower priority or disable it entirely.
Save and Exit: Save the changes you've made and exit the BIOS/UEFI setup. The computer should now attempt to boot from your local drive.

If the issue persists, double-check that no network devices (like USB-to-Ethernet adapters) are forcing a network boot. In managed environments, consult your IT department, as they may have specific configurations that require PXE booting for certain functions.