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I want to try doing a PXE install for the first time.

Every single tutorial I've read seem to indicate it requires a DHCP server configured to point to the TFTP server with the boot image. I don't understand why DHCP should be required though, isn't it possible to just manually configure computer's IP and network settings, and manually specify the IP where the TFTP server is located?

If not, is there any particular reason why you wouldn't be allowed to do this, or given a simple prompt in the pxe menu asking to manually specify the network path?

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A DHCP server gives the client the IP address, static route, DNS server, a filename to load, and the "next-server" name or IP to load it from, and other config details.

The problem is "where are you going to configure those details if not from DHCP"?

Does your BIOS give you that option, fields to enter those details? Most likely not.

You could create your own custom ROMs (e.g using ipxe) for certain NICs with this information hard-coded - but why? Not only would you have to make a unique individual ROM for each NIC (for the IP address), but hard-coded configuration details nearly always end up being a pain because details change and you need to be able to change them easily....which you can do with a DHCP or bootp server, simply by editing the dhcpd.conf

There's nothing preventing a PXE ROM from having a configuration menu (in fact, I have seen some servers with the ability to specify a NIC's IP address and some other details - mostly for remote management cards like Dell iDRAC and HP iLO and Sun LOM), but there is little incentive for manufacturers to do so - this is an already solved problem, and DHCP / bootp is the solution.

  • Thanks for the answer. The configuration menu you mention is basically what I was looking for. It would be nice if when you select the onboard nic as your boot device, if it would give you a basic text menu letting you specify your IP and also the TFTP server location. But sounds like this is only available on very few cards. – user142968 Nov 22 '15 at 4:27
  • OK, let's say that the BIOS lets you set an IP address etc for a NIC....and successfully loads, say, gpxelinux.0 from the configured next-server. Where does gpxelinux.0 get it's network configuration from? The BIOS config is only valid while the BIOS code is running, and there's no way for that to persist from the BIOS to the next program run - it has to run a dhcp query or have the network config hard-coded somehow. you can see this yourself if you watch a network boot in progress, there will be multiple DHCP requests as each stage of the boot needs to get an IP address, etc. – cas Nov 22 '15 at 23:22

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