NetBoot server principle

Revision as of 08:26, 21 August 2014 by WikiFreak (talk | contribs)



Requirements

To setup a PXE NetBoot infrastructure you need:


As you can see on the previous picture, a DHCP server + TFTP server are mandatory.

It's also good to have a DNS server to use names instead of IP @.


Overview of a NetBoot sequence

NetBoot sequence overview (FreeBSD (c))


1. Client broadcasts a DHCPDISCOVER message.

2. The DHCP server responds with:

  • the computer IP address,
  • TFTP server address (called "next-server"),
  • PXE boot filename to load,
  • NetBoot root-path values.

3. The client sends a TFTP request to "next-server", asking to retrieve the PXE filename.

4. The TFTP server responds and sends filename to client.

5. Many things here:

  • The client executes filename, which is in PXE format.
  • The PXE menu will be display so the user can choose which kernel to load
  • Then PXE loads the kernel.
  • When the kernel executes, the root file system specified by root-path is mounted. If it's a diskless workstation then the client distribution will be mounted in NFS mode.



Diskless NetBoot

The following picture describes the same thing as before in the sequential order:

NetBoot overview step by step


The same one, with a few hand-writing.

PXE principle


Note that you have to prepare the image before being able to boot on it. ^^




References

The 1st overview picture comes from the FreeBSD forum: http://www.nl.freebsd.org/doc/handbook/network-diskless.html