[klibc] ipconfig and boot filename option

[Άλκης Γεωργόπουλος]

Peter,

thank you very much for this option, I wasn't aware of it. I don't
have much experience on Linux and I'm straggling to get my school labs
in order.

But I didn't understand how "ipappend 2" would help. It passes the mac
address, but what we need is
ip address, mask, gw, tftp root path
Sounds more like "ipappend 1". So, new questions:
1) How can we retrieve these kernel parameters to do
ipconfig addr:server:gateway:netmask:hostname:interface:proto

2) How can we do something like this from a boot floppy / cd / disk?

3) Why in http://syslinux.zytor.com/faq.php you say that it's not recommended?

I'm keeping this short, so I'll just say thanks for your valuable time!
Alkis

2008/5/24 H. Peter Anvin <hpa at zytor.com>:
> Άλκης Γεωργόπουλος wrote:
>>
>> Hi,
>>
>> ipconfig is used in ltsp (thin clients) initramfs. Some of the users
>> have to have 2 dhcp servers in ltsp environments, so they hit on this
>> problem:
>> The first dhcp request is from the pxe rom boot code. This code
>> ignores any dhcp offers that don't have a filename field. So they
>> always get the correct address, from the ltsp server.
>>
>> The second dhcp request (in initramfs) is done by ipconfig. And here
>> is the problem, ipconfig accepts any offered addresses, even those
>> that don't have the filename option. So the clients may get their ip
>> from the wrong dhcp server (e.g. the adsl router) and fail to boot.
>>
>> What I'm asking for is a command line option,
>> that forces ipconfig to ignore all DHCPOFFERs that do not have a
>> filename option,
>> so that it only accepts ip addresses from ltsp servers.
>>
>
> I think that would be a very bad idea.
>
> A much better idea would be to use the "ipappend 2" option to pxelinux,
> which passes the hardware address of the booting interface to the kernel.
>  Then just bring *that* interface up.
>
>        -hpa
>