Open source code for DHCP and webserver for LPC2294 and CS8900

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I know asking the earth.  I have found webservers with fixed IP addresses
but not with DHCP.

Are there any alternatives I can port easily given I'm a fairly newbie to C!

Many thanks in advance.



Re: Open source code for DHCP and webserver for LPC2294 and CS8900
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A web server itself has neither a fixed nor a dynamically assigned IP
address.

Ignoring some custom/tiny servers for microcontrollers, a web server
is an application running under a host operating system, (doesn't
matter if the OS is a full blown system or a minimal kernel,) and it
will use the IP address configured by the hosting environment.

Check the services provided by your host environment to see how to get
an address via DHCP.

Roberto Waltman

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Re: Open source code for DHCP and webserver for LPC2294 and CS8900

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Many thanks for your post.

I was looking for a dedicated microcontroller webserver for a local network
with some a system where I could type in http://embedded_system_name/ and
get a status page.  I am aware that this is not just DHCP but somewhat more.
I was wondering if there were any open source software which could do this
or I could modify.



Re: Open source code for DHCP and webserver for LPC2294 and CS8900
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DHCP supports something that is called DHCP hostname. The purpose of
this is that a DHCP client can pass a hostname to the DHCP server
which in turn can do two things.

a) it can assign an IP that is maybe influenced by the name you pass
in.

b) it can comunicate the IP asigned and the name to the nameserver in
use.

Both operations can be implemented differently if at all, but
obviousely your DHCP client impelentation would have to support DHCP
hostname.

As the other poster mentioned already, servers (no matter wether they
are embedded or not) get fixed IPs assigned to keep things simpler.
Thereafter it's the nameservers job to map a name to said IP. If the
DHCP server comunicates the assigned IP to the nameserver it's not
needed that the IP is always the same, but such configurations seem to
be rare IMHO.

Implemeneting DHCP to one of the available freeware TCP stacks should
not be rocket sience. Read the DHCP RFC's and study the stacks lower
level IP networking code and you surely will get an idea on what to
do.

HTH

Markus

Re: Open source code for DHCP and webserver for LPC2294 and CS8900

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To some extent, it's quite self-contradictory to be using DHCP on one
hand, i.e. dynamic IP and hostname assignment, but still require a
static published DNS host name.

There are basically two solutions to this:

1) kill part of the dynamicity of DHCP (--> pre-assigned DHCP responses
   for known MAC addresses)

2) make the IP <-> hostname mapping of your responsible DNS server
   dynamic, even though DNS is meant to be mostly static (--> update
   DNS tables by request from the embedded device, as part of its
   start-up procedure).

What both cases have in common is that the embedded system itself has
little or nothing to do with them --- the bulk of the work has to be
done on an organizational level, i.e. by your local network's
adminstrator(s).  They have to maintain the static DHCP tables, or
make sure the local DNS server accepts such dangerous requests from
otherwise completely unknown devices.

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

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