iPXE network boot

Updated: July 17, 2026

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This topic explains the iPXE network boot feature on NCS 1004, which enables you to download and install a fresh IOS XR ISO image from an HTTP, FTP, or TFTP server when the router cannot boot from its local storage.

iPXE (Preboot eXecution Environment) network boot feature enables you to download and install a fresh IOS XR ISO image from an HTTP, FTP, or TFTP server.

iPXE is a pre-boot execution environment included in the network card of the management interfaces. It operates at the system firmware (UEFI) level of the chassis. You can use iPXE to reimage the system and boot the chassis if there is a boot failure or no valid bootable partition. iPXE downloads the ISO image, installs the image, and then boots into the new installation.

Note

The time taken for iPXE to download the ISO image depends on the network speed. Ensure that the network speed is sufficient to complete the image download in less than ten minutes. The chassis reloads if the image is not downloaded within ten minutes.

iPXE acts as a bootloader and provides the flexibility to choose the image that the system will boot based on the Platform Identifier (PID), the Serial Number, or the management MAC address. You must define iPXE in the DHCP server configuration file.

Configure a DHCP server for iPXE boot

Ensure your DHCP server supports iPXE network boot for NCS 1004, allowing devices to receive correct boot files in IPv4-only, IPv6-only, or dual-stack setups.

A DHCP server must be configured for IPv4, IPv6, or both communication protocols.

Note

For DHCPv6, a routing advertisement (RA) message must be sent to all nodes to indicate how to obtain the IPv6 address. The Router Advertisement Daemon (radvd) enables clients to send DHCP requests.

interface eth3
{
        AdvSendAdvert on;
        MinRtrAdvInterval 60;
        MaxRtrAdvInterval 180;
        AdvManagedFlag on;
        AdvOtherConfigFlag on;
        prefix 2001:1851:c622:1::/64
        {
                AdvOnLink on;
                AdvAutonomous on;
                AdvRouterAddr off;
        };
};

Procedure

Create the dhcpd.conf file (for IPv4, IPv6 or both communication protocols), dhcpd.conf file (for IPv6), or both in the /etc/ directory.

This configuration file stores network information, such as the path to the script, the location of the ISO install file, the location of the provisioning configuration file, the serial number, and the MAC address of the chassis. You can create this file for IPv4, IPv6, or both communication protocols.

Test the server once the DHCP server is running.

Use the MAC address of the chassis.

Example:

host ncs1004
{
hardware ethernet ab:cd:ef:01:23:45;
fixed-address <ip address>;
filename "http://<httpserver-address>/<path-to-image>/ncs1004-mini-x.iso";
}

Use the serial number of the chassis.

Example:

host demo {
option dhcp-client-identifier "<chassis-serial-number>";
  filename "http://<IP-address>/<hardware-platform>-mini-x.iso";
  fixed-address <IP-address>;
}

The serial number of the chassis is derived from the BIOS and is used as an identifier.

The DHCP server is configured for iPXE boot, enabling NCS 1004 devices to obtain the correct boot file in IPv4, IPv6, or dual-stack environments.

host 10.89.205.202 {
    hardware ethernet 40:55:39:56:0c:e8;
    fixed-address 10.89.205.210;
    if exists user-class {
        if option user-class = "iPXE" or option user-class = "\x04iPXE" {
            filename "http://10.89.205.127/box1/ncs1004-x64.iso";
        } else {
            filename "http://10.89.205.127/box1/startup.cfg";
        }
    } else {
        filename "http://10.89.205.127/box1/startup.cfg";
    }
}

Boot NCS 1004 using iPXE

Boot NCS 1004 using iPXE to reimage the chassis with a network-based ISO image.

Use iPXE to reimage NCS 1004 from the network when you want to deploy or upgrade software without relying on local storage. This process uses DHCP and HTTP servers to deliver the ISO image.

Before you begin

The DHCP server is set up and running. See Set up a DHCP server for iPXE boot.
Log in to the System Admin console using the admin command.

Procedure

Run the hw-module location all bootmedia network reload command in the System Admin console to start the iPXE boot process and reimage the chassis.

Example:


sysadmin-vm:0_RP0# hw-module location all bootmedia network reload
Tue Feb 12 15:29:57.376 UTC
Reload hardware module ? [no,yes]

Enter yes when prompted to confirm the reload.

The iPXE bootloader contacts the DHCP server, downloads the ISO image, and installs it. Monitor the progress on the console.

iPXE 1.0.0+ (3e573) -- Open Source Network Boot Firmware -- http://ipxe.org
Features: DNS HTTP TFTP VLAN EFI ISO9660 NBI Menu
Trying net0...
net0: c4:72:95:a6:14:e1 using dh8900cc on PCI01:00.1 (open)
[Link:up, TX:0 TXE:0 RX:0 RXE:0]
Configuring (net0 c4:72:95:a6:14:e1).................. Ok
net0: 10.37.1.101/255.255.0.0 gw 10.37.1.0
Next server: 10.37.1.235
Filename: http://10.37.1.235/ncs1004/ncs1004-mini-x.iso
http://10.37.1.235/ncs1004/ncs1004-mini-x.iso... 58%

NCS 1004 boots and installs the specified ISO image from the network. You can monitor and verify installation progress in the System Admin console.

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