Thanks Robert and Dave,

>The dhcp.client -h option provides two services, one is to override the
>hostname that may be supplied by the server, and the other is to >pass the  hostname to the server. This information 
might be a bit >dated as I have not  check host behavior recently, but what the -h >option does is mimic a Windows DHCP 
client implementation. When >invoking DHCP Windows would include its  current hostname in the >DHCP request and its 
hostname could not be overridden. What the >DHCP server does with this information depends on the server >configuration.
 A Windows DHCP server may use this information to
>update the nameserver while another implementation may not (for >example you overrode locally the hostname it intended 
to assign). The >main reason it was added is that cable internet service providers at the >time were using the hostname 
as a form of authentication. Your >home system ( Only Windows would be supported of course ;) ) was >assigned a 
'Computer Name', and when it booted, it would send this >name (hostname) as part of the DHCP request. If the hostname 
was >not present, the DHCP server would not respond.  I have not had a >cable ISP for some time, but I don't think they 
require this any longer. 
> 
> Dave  



Fantastic infos. Things are fine now.

(The server in question is a Novell DHCP V3)

Swiching the server into debug mode and starting "dhcp.client -h somename"  showed that the name is indeed submitted .
At least mac and string reached the server.
(core_networking] / trunk / services / dhcp.client / dhclient.c )
...
for(count=1;count<=8;count=count*2){
    result = send_packet (interface, (struct packet *)0,
      &raw, outgoing.packet_length,
      raw.siaddr, &to, (struct hardware *)0);
... ?


However:

From a QNX standard user/Admin_of_SomeCompany point of view reading the docs it is difficult to.... 

(http://www.qnx.com/developers/docs/6.3.0SP3/neutrino/utilities/p/phlip.html ) :

[]
ID 
Normally, you don't need to fill in this field. Typically, a DHCP server allocates an identity for a client and sends 
that identity to the client automatically; the identity then becomes the client machine's hostname. Sometimes, an ISP 
will provide an identity separately and a client is expected to enter this identity as a security measure when they log 
in. If you are told to use such an ID, enter it here, otherwise leave the field blank. 
[]

....guess where to set the ID, as the next picture of phlip' s Devices Tab shows the Manual mode and not the dhcp mode. 
  

So for the mininum I would appreciate a hint to the -h option of dhcp.client from within the doc-text block snipplet 
above.

I will file a doc PR as this seem to be a FAQ:
see:
http://community.qnx.com/sf/go/topc1548

Thanks again for all Your expertise on this.
Jeevan



> 
> 
> > -----Original Message-----
> > From: Robert Craig
> > Sent: Wednesday, March 05, 2008 3:03 PM
> > To: general-networking
> > Subject: RE: RE: dhcp.client qs:
> > 
> > The mysteries of booting are easily forgotten... :->>
> > 
> > With regards to the hostname,
> > 
> > The -h modifies the name that the client knows itself by.
> > 
> > The server question that you're asking is two fold.
> > 
> > Firstly, does our client return the new hostname to the server (I'd have
> > to
> > check, or maybe someone else will jump in and answer).
> > 
> > Secondly, will the server update the DNS name data base if it is sent the
> > information by the client.  For this, the server has to be running a
> > Dynamic
> > DNS server which allows the DHCP server to update the DNS database with
> > client information.   I suspect that our named might be of a vintage where
> > this isn't supported but, again,...