<script type="text/javascript"> slides = { title: 'Netboot', copyright: 'Dr Joe Francom (Utah Tech University)', course: 'IT 3110', }; </script>

IT 3110 : Advanced System Administration

Netboot

Netboot

  • Also known as PXE boot
  • PXE = Preboot eXecution Environment
  • client has to have pxe capable nic
  • retreive boot files from network

Why?

  • Easier?
  • Eliminates need for disks?

Implementation

  • Add option to dhcp server so that host knows where to go to find correct image to load (bootstrap program) or (NBP = Network Bootstrap Program)
  • Usually that 'image' is made available via tftp
  • TFTP = Trivial File Transfer Protocol

DHCP

  • Client has to broadcast a special Discover message to port 67 (DHCP)
    • asks for ip and special booting params
    • if pxe client contact dhcp that isn't configured to send boot params, it won't be able to boot
  • Server sends back offer
  • Client uses offer (IP address) to find the tftp server and NBP
  • NBP is loaded into RAM and booted

TFTP

  • Simple to implement ftp server
  • fast
  • no authentication

Notes

Rather than blindly following slides. Contemplate what you are doing. If I ask you to netboot a different version of ubuntu, how would you do it.

  • Example: ubuntu 19.10 netboot
    • You need to find the netboot.tar.gz file and put it in the ftp directory