Does RTEMS really support client DHCP?

[Tim Cussins]

Hi

One things I found with several routers is that the total reply length
was less than 300 bytes - this is valid for DHCP, but BOOTP requires at
least 300 bytes.

The RTEMS BOOTP implementation ignores any response less than 300 bytes,
last I looked. Might be a lead on your linksys problem.

HTH,
Tim



On Tue, 2008-10-28 at 02:58 -0400, Gene Smith wrote:
> How do you enable DHCP client support in RTEMS? In networkconfig.h you 
> define RTEMS_USE_BOOTP to enable BOOTP/DHCP. But when this happens I 
> only see BOOTP request broadcasts sent from the RTEMS unit, but get no 
> answer. When I plug in my other device, Macraigor JTAG described below, 
> I see packets DHCP Discover and DHCP Request and the address (and 
> hostname) are obtained. (This is looking with Wireshark.)
> 
> I see a large file, *dhcp.c, in RTEMS libnetworking but it is not 
> included in my code for some reason. Also, see references on the list to 
> BOOTP not working with Linksys routers and/or dnsmasq. So probably need 
> DHCP to work if possible. My wireless router is Linksys and it contains 
> dnsmasq.
> 
> My previous post on this subject is included below since it was a reply 
> to a very old post which may not be visible in threaded view mode. 
> Should have made a new post.
> 
> -gene
> 
> gene wrote 10/28/2008:
> > The question below was asked on the list some time ago but never got a 
> > reply. I have also been trying to figure out the same question.
> > 
> > Right now I have a non-RTEMS Macraigor jtag debugger box on my local 
> > network. I have given it a hostname "mpdemon" since that is what the 
> > product is. The host name is originally entered through the serial 
> > console on the jtag box. I have also configured the jtag box to obtain 
> > its IP address with DHCP (static is the other option). When the box 
> > powers up it obtains its address from my server (as I would expect) and 
> > it is ping-able and it webpage is accessible using the name mpdemon (or 
> > the longer name mpdemon.mylocaldomain). My DNS server (dnsmasq) was 
> > never told about the name "mpdemon" but now understands it when used by 
> > any host.
> > 
> > As the question below points out, in RTEMS networkconfig.h you can't 
> > seem to specify the hostname when BOOTP (really DHCP?) is enabled. So is 
> > it possible to do in RTEMS what the Macraigor jtag box can do using DHCP 
> > (automatically make its hostname known in DNS)?
> > 
> > -gene
> > 
> > Alex Holeczy wrote, On 06/03/2005 09:42 AM:
> >> > 
> >> > I am working on an RTEMS application where I am configuring the network 
> >> > interface to use BOOTP/DHCP to get the IP address for the system.
> >> > 
> >> > In order for a user application to connect to the system, I would like 
> >> > to specify the network hostname of the system and I would prefer not 
> >> > having to configure the DHCP daemon with this information.  This would 
> >> > allow the user application to connect to the system without knowing the 
> >> > IP or mac address.
> >> > 
> >> > In the network configuration structure, there is an entry for the RTEMS 
> >> > application to provide a hostname.  It seems that this hostname is only 
> >> > used locally and does not get included in the bootp request packet.
> >> > 
> >> > Is there currently a way for an RTEMS application to provide the DNS 
> >> > server with its local hostname?
> >> > 
> >> > What would be the downsize of modifying the bootp request packet to 
> >> > include the host name option?
> >> > 
> >> > 
> >> > Regards,
> >> > Alex
> 
> _______________________________________________
> rtems-users mailing list
> rtems-users at rtems.com
> http://rtems.rtems.org/mailman/listinfo/rtems-users