When your computer is powered on, among the first parts to "wake up" is the BIOS. This is like a nerve center, or the medulla of your brain.
The BIOS has pre-saved instructions to hand off control to another section of the computer which holds an operating system, usually it's Windows installed on a hard drive within the computer. We call these sections "environments." This is like the medulla (low level functioning) handing off control to your cerebral cortex (high level functioning).
The BIOS has options on which environment to hand off control to. The choice is determined by a pre-programmed boot order. The boot order says "Try booting to X first. If X is not there, try booting to Y."
One type of environment is called PXE, pronounced "Pixie" in the IT industry. PXE exists so the BIOS can boot to an environment through a network connection instead of a hard drive. The BIOS detects the ethernet connection, then detects a remote PXE server to talk to, then hands off control to the remote server at the other end of that network connection. The hard drive is out of the loop.
The PXE hand off must be pre-configured in BIOS. It is not a default (from factory) setting in BIOS. PXE must manually be enabled, and the boot order must manually be set to boot to PXE.
In the case of the election server, if a bad actor does not want to remotely boot through PXE, he can just disable the connection to the remote PXE environment. No one will notice as the machine boots to its local hard drive. However, if the connection is establish, just reboot the system and it's instantly running from a remote environment located anywhere.
It's a broadcast query, as the IP address settings are not known at the time.
Basically, the for a DHCP request (which is how both PXE and assigning your laptop an IP address over DHCP work), the computer yells to everything that will listen "Hey, I'm here, give me an IP address." (The actual message is called DHCPDISCOVER).
The computer will accept the first DHCPOFFER it hears back.
The PXE boot settings are optional additional fields that can be set on the DHCP server.
To clarify, broadcast basically sends a message to the IP address 255.255.255.255 (an IP address where every bit is 1). Everything on the network that sees the message has the opportunity to respond to this.
I work for the company that made the server.
I'll translate this into normie speak:
When your computer is powered on, among the first parts to "wake up" is the BIOS. This is like a nerve center, or the medulla of your brain.
The BIOS has pre-saved instructions to hand off control to another section of the computer which holds an operating system, usually it's Windows installed on a hard drive within the computer. We call these sections "environments." This is like the medulla (low level functioning) handing off control to your cerebral cortex (high level functioning).
The BIOS has options on which environment to hand off control to. The choice is determined by a pre-programmed boot order. The boot order says "Try booting to X first. If X is not there, try booting to Y."
One type of environment is called PXE, pronounced "Pixie" in the IT industry. PXE exists so the BIOS can boot to an environment through a network connection instead of a hard drive. The BIOS detects the ethernet connection, then detects a remote PXE server to talk to, then hands off control to the remote server at the other end of that network connection. The hard drive is out of the loop.
The PXE hand off must be pre-configured in BIOS. It is not a default (from factory) setting in BIOS. PXE must manually be enabled, and the boot order must manually be set to boot to PXE.
In the case of the election server, if a bad actor does not want to remotely boot through PXE, he can just disable the connection to the remote PXE environment. No one will notice as the machine boots to its local hard drive. However, if the connection is establish, just reboot the system and it's instantly running from a remote environment located anywhere.
If done right, no one notices.
Not necessarily. An attacker could bring their own dhcp server and the host will boot on whatever DHCP config it receives first.
It's a broadcast query, as the IP address settings are not known at the time.
Basically, the for a DHCP request (which is how both PXE and assigning your laptop an IP address over DHCP work), the computer yells to everything that will listen "Hey, I'm here, give me an IP address." (The actual message is called DHCPDISCOVER).
The computer will accept the first DHCPOFFER it hears back.
The PXE boot settings are optional additional fields that can be set on the DHCP server.
To clarify, broadcast basically sends a message to the IP address 255.255.255.255 (an IP address where every bit is 1). Everything on the network that sees the message has the opportunity to respond to this.