XDMCP Problems - Possible fix, please try

[Andrew DeFaria]

Harold L Hunt II wrote:

> Andrew,
>
> Andrew DeFaria wrote:
>
>> Sorry for the delay. We were having problems with our router and 
>> general networking issues - not an nice environment to test things 
>> like remote X...
>>
>> Well I tried that too but it didn't work. The symptoms are exactly 
>> the same.
>>
>> For kicks I tried the following:
>>
>> While on sonslinux I attempted to start another X server like so:
>>
>> $ X -query sonslinux :1
>>
>> This brought me to another console (that I could get to by doing 
>> Alt-Ctrl-F8 whereas my previous console is at Alt-Ctrl-F7) and 
>> started X but KDM did not attach to it. Monitoring I see:
>
> That is genius! 

Why thank you!

> I never thought of forcing people to try to make a connection on the 
> actual box itself.
>
> I ran the same command on my linux box and confirmed that it does work.
>
> I then edited (for my display manager and distribution, this will be 
> different for you) /etc/kde3/kdm/kdmrc, changed the following:
>
> [XDMCP]
> Enable=true
>
> to
>
> [XDMCP]
> Enable=false
>
> Then I restarted kdm ('/etc/init.d/kdm restart' for my dist), and ran 
> 'X -query %hostname% :1' again and waited about five minutes.  Before 
> five minutes, I saw nothing: nothing special in the log files and no 
> login screen on Ctrl-Alt-F8.  Then, after about five minutes, I saw 
> that the /var/log/XFree86.1.log file (and the console from which I 
> started X) both said:
>
> XDM: too many retransmissions

Well you see that's sorta the problem. In my distro (SuSE 8.2) it's at 
/opt/kde/share/config/kdm/kdmrc but the problem is that it already says 
true! In mine is says:

[Xdmcp]
Enable=true

I don't think that the capitalization of Xdmcp is significant (yours is 
all caps while mine is initial cap - tried changing it - didn't help) 
nor do I think that case is significant in the true/false value. Also, I 
cannot restart kdm with /etc/init.d/kdm restart as I have no 
/etc/init.d/kdm! I have an /etc/init.d/xdm though. When I do 
/etc/init.d/xdm stop it says "Shutting down service kdm" and it does 
shut it down. Similarly /etc/init.d/xdm start starts it.

So I have no ideas why this is still not working.

> We now know that the failure mode when XDMCP is disabled is that after 
> a five minute wait you get a message about too many retransmissions, 
> even if attempting to connect from the machine back to itself via 
> '-query %hostname%'.  This is the same failure mode that happens with 
> XWin.exe, but it eliminates lots of possible problems.
>
> To solve your problem, you need to revisit the instructions for 
> enabling XDMCP on your Linux box:
>
> http://xfree86.cygwin.com/docs/faq/cygwin-xfree-faq.html#q-mandrake-8.1-xdmcp 
>
>
> Those instructions are not complete, but they are a start that should 
> be able to point you in the right direction.  Confirm that you can 
> create a local connection via XDMCP before attempting a remote 
> connection with XWin.exe.  Please report your results to the list so 
> that I know if you have fixed your problem or not.
>
> Thanks for your help in debugging this,

Well I've been there before and all it really says is to make sure that 
[Xdmcp] has Enable=true, which mine does. Still no does not work.
-- 
I've always wanted to be somebody, but I should have been more specific.