Remote use of XDMCP

[Robert Brockway]

On Sun, 19 Mar 2006, James Knott wrote:

> I currently have XDMCP running well on my local network, in that
> computers on my home network can use it to access other computers.
> However, when I try to connect via WiFi & VPN, one computer that works

So you are using the VPN at all times when connected locally?

What sort of VPN are we talking about here btw?

Is there some reason you don't want to use the WiFi without the VPN?  If 
it is security, there is a lot to be said for WPA.

> well on the local lan, cannot connect.  I've used ethereal to see what's

I don't suppose you could connect it via a wire to test xdmcp with 
wireless right out of the equation?  I'd say you would have already done 
this if you could.

> happening.  In the list below, the letters A & B indicate the source of
> the packets.  "A" (10.x.x.x address) is a notebood connected via WiFi &
> VPN and "B" (192.168.x.x) is my main desktop system. Both systems are
> SUSE 10.0.  Ethereal, running on both the notebook and desktop shows the
> following.
>
> A XDMCD Query
> B XDMCP Willing
> A XDMCP Request
> B XDMCP Accept
> A XDMCP Manage (repeats 7 times)
> B XDMCP Failed.
>
> So, it's obvious the two systems are communicating, but unable to run an
> X session.  Is there something that prevents a routed connection from
> working?  Perhaps an address range issue?  Other ideas?

Probably not related to the address range based on the info you relate 
from ethereal.  You can check the relevant Xaccess file to make sure.

Similarly it does seem that udp/177 is getting through.  Use netcat to be 
sure.

It's unlikely to be WiFi related unless your getting abysmal performance.
I've used xdmcp over (WEP & WPA encrypted) links plenty of times with few 
problems.

Could it be an MTU or packat fragmentation problem passing over the VPN?

Rob

-- 
Robert Brockway B.Sc.        Phone:          +1-905-821-2327
Senior Technical Consultant  Urgent Support: +1-416-669-3073
OpenTrend Solutions Ltd      Email:          support-wgAaPJgzrDxH4x6Dk/4f9A at public.gmane.org
                              Web:            www.opentrend.net
We are open 24x365 for technical support.  Call us in a crisis.
--
The Toronto Linux Users Group.      Meetings: http://tlug.ss.org
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://tlug.ss.org/subscribe.shtml