Re: [Etherboot-users] REQUIRE_VCI_ETHERBOOT Question

[Jim M. <ja...@Mc...>]

On Thu, March 9, 2006 2:14 pm, Marty Connor wrote:
> On Mar 9, 2006, at 4:52 PM, lonnie=40outstep.com wrote:
>> When a boot client does a broadcast for a DHCP request, then there
>> could be more than 1 DHCP server responding and the client would
>> receive requests from all responding DHCP servers looking for the
>> one that accepted that particular client and gave it a lease, right?
>
> It's more elaborate than that.  PXE says the client should wait for
> up to 3 DHCP offers, and pick the one it likes the best (correct me
> if I'm wrong, PXE mavens).
>
>> Would this also mean that, in general, for all of the DHCP servers,
>> then if only one of the had the client MAC address in their list
>> then that would be the request that would have the valid
>> information (IP, gateway, etc....) for that client?
>> I guess what I am getting at is that it is probably ok for there to
>> be multiple DHCP servers on the net and subnets as long a only one
>> of them had the client address as an acceptable MAC address.
>
> It depends on if they're (the DHCP server) are =22authoritative=22 for
> the subnet or =22not authoritative=22 in ISC dhcpd.conf parlance.
> If they have the =22not authoritative=22 directive turned on, they don'=
t
> say anything. If they're authoritative, I believe they say =22no lease=22=

> if you don't have a pool of addresses defined.
>
>> The problem with changing ports for the DHCP server and Etherboot
>> is that there might already be other DHCP servers on those ports
>> without us bing aware of it by some chance and then we would still
>> have multiple requests beign fielded by multiple DHCP servers and
>> in which the problem is really not solved.
>
> We're looking at allowing people to put STATIC information in their
> Etherboot configuration so that no DHCP server is required to load a
> file.
> This means that someone could mess up and walk on an IP address on
> the LAN, but this is already possible on just about any device I know
> about.
> The consequences would be between you and your LAN administrator if
> you blow it.
>
> Isn't there some way to use DEFAULT_BOOTFILE to get what you want
> using Etherboot?
>
>      setting DEFAULT_BOOTFILE to:
>
>          tftp://192.168.1.xxx/tftpboot/lts/kernel.nb
>
> (I believe) would get an IP address from a DHCP server, and then
> (assuming the DHCP server didn't give a filename) would use the
> DEFAULT_BOOTFILE.
>
> I even found an old patch that would FORCE_BOOTFILE (although I would
> rename it FORCE_DEFAULT_BOOTFILE :) that ignores all the DHCP
> filenames and uses the one you supplied.
>
> This strikes me as a likely scenario.  You can get an IP, Router,
> DNS, etc, but you can't modify the DHCP server to do the filename
> thing, even though you have your own little tftp server (they're so
> much less objectionable than DHCP servers to LAN admins, after all).
>
> So you get everything from normal DHCP except DEFAULT_BOOTFILE, and
> you get your kernel from where you need to.
>
> Does this help?

He'd still be missing the root-path option that is required by LTSP
(assuming he's using LTSP).

Fortunately, it's possible to fix that in LTSP (Don't ya just love open
source?)

Jim.


>
> Marty
>
> --- etherboot-5.3.6/src/core/nic.c      2003-12-13 07:27:21.000000000
> +0100
> +++ etherboot-5.3.6.new/src/core/nic.c  2003-12-21 15:22:27.000000000
> +0100
> =40=40 -267,7 +267,11 =40=40
>          rpc_init();
>   =23endif
>   =23ifdef DEFAULT_BOOTFILE
> +=23ifdef FORCE_BOOTFILE
> +       kernel =3D DEFAULT_BOOTFILE;
> +=23else
>          kernel =3D KERNEL_BUF=5B0=5D =21=3D '=5C0' ? KERNEL_BUF : DEFA=
ULT_BOOTFILE;
> +=23endif /*FORCE_BOOTFILE */
>   =23else
>          kernel =3D KERNEL_BUF;
>   =23endif
>
>
>
>
> -------------------------------------------------------
> This SF.Net email is sponsored by xPML, a groundbreaking scripting
> language
> that extends applications into web and mobile media. Attend the live
> webcast
> and join the prime developer group breaking into this new coding
> territory=21
> http://sel.as-us.falkag.net/sel?cmd=3Dlnk&kid=3D110944&bid=3D241720&dat=
=3D121642
> _______________________________________________
> Etherboot-users mailing list
> Etherboot-users=40lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/etherboot-users
>