Does RTEMS really support client DHCP?

Gene Smith gds at
Tue Oct 28 06:58:39 UTC 2008

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 

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 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

More information about the users mailing list