topic Re: xdm and DHCP hosts in Operating System - Linux

xdm and DHCP hosts

tony j. podrasky — Thu, 30 Jun 2005 12:00:37 GMT

Hi Folks;

O/S: RedHat 3.0 AS

I'm running xdm and have two issues:

xdm will not serve a computer that does not have a hardwired IP address. All of my computers are able to open up an X-session
(with Reflections X) because they are in the /etc/hosts file - but when I try it with a laptop that uses DHCP, I get a timeout. If give it a hard address, or I go into my /etc/hosts files and add in the laptop's DHCP IP-du-jour, and give it a hostname, it works fine.

The xdm-error log has the following entry:
Possible DNS spoof attempt.xdm error (pid 12777): Cannot convert Internet address 15.19.93.48 to host name.

The second issue is when you bring up a BROADCAST session with the chooser, All the other hosts offering sessions show up as "0 users load 2.2.1.1" but the Linux box shows up as "This account is currently not available" - but you CAN get it to serve you.

I've tried setting the xdm file in PAM.D to
all "optional" fields, which didn't fix the
problem but did lead to some exciting anomolies
:-)

regards,
tonyp

tony.podrasky@hp.com

Re: xdm and DHCP hosts

tony j. podrasky — Thu, 30 Jun 2005 12:16:58 GMT

Disregard the 2nd problem (This account
currently not available). That is an error
message from xdm because the call to Xwilling
used the user "nobody", which does not work
on my system. Once I got rid of the "su"
section, it works fine.

regards,
tonyp

Re: xdm and DHCP hosts

Ivan Ferreira — Thu, 30 Jun 2005 13:46:15 GMT

For DHCP clients, i think you should use dynamic DNS, so the host name can be resolved.

Re: xdm and DHCP hosts

Gopi Sekar — Thu, 30 Jun 2005 23:39:49 GMT

looks like your xdm is configured to resolve back the connections with the host name list. if it can not find, it just rejects the connection.

check /etc/X11/xdm/Xaccess file, it specifies the access control file for X11. so make sure you have enabled all hosts can get a xdm session

Hope this helps,
Gopi

Re: xdm and DHCP hosts

Steven E. Protter — Fri, 01 Jul 2005 07:43:31 GMT

The most likely cause of the problem is that the DHCP client is not in the same collision domain(VLAN) as the DHCP server.

xdm broadcase only works inside the VLAN, it won't let X clients outside the VLAN, even though they can ping to see the X servers.

Tell me please about the exciting anomalies.

;-)

SEP

Re: xdm and DHCP hosts

tony j. podrasky — Tue, 05 Jul 2005 10:13:56 GMT

The problem is that I am trying to access
the XDMCP server from a DHCP client on
another network, far far away...

I use a LINUX box as my office machine.
To access my e-mail when I am out of the
office, I lug around a laptop running XP.

The work-around is the fire-up REFLECTIONS X
on the laptop. Then use a session
to the Linux box, set the display variable
to the XP box, then fire-up Mozilla on the
Linux box.

Thanx to all for the help.

regards,
tonyp