Discussion between Alan Curry and hetaoblog - 2012-07-30

last day (14 days later) »

7:12 AM

1

Q: cygwin help: Xlib: connection to "ip:0.0" refused by server

I followed cygwin user guide as below: http://x.cygwin.com/docs/ug/using-remote-apps.html on windows xp, i started Cygwin/X->XWin server, EXPORT DISPLAY=:0.0 ssh -Y user@ip i saw below warning Warning: No xauth data; using fake authentication data for X11 forwarding. after login, i typed...

cygwin xserver xauth

Is "clientip" the Cygwin machine or the other one? (I have to ask because people sometimes get confused about the words "client" and "server" with X, thinking that the machine on their desk can't be the "server" - it is!)

the ""clientip:0.0" i'm referring to the windows xp machine where i install my cygwin and xserver software.

Can you run "xauth list" locally on the Cygwin machine?

i run the command but got nothing

what command line did you use to start Cygwin/X?

7:12 AM

i click 'start->programs->cygwinx->xwin server'; when i try to input 'startxwin', it said 'startxwin: Another X server instance is running on DISPLAY :0
: Resource temporarily unavailable'; i also tried startx and then do ssh -Y, but the result is the same.

The "add comment" thinks we're commenting too much.

hi, Alan,

thx for your help:)

OK, first of all, can you run any local cygwin commands that use the X display? Did it come with any of the demos like xlogo?

Just want to figure out if it works at all.

looks as if i'm not doing it right, when i type xclock or xlogo, it always said command not found

is 'start->programs->cygwinx->xwin server' the right way to start X?

all right, I'm not sure what cygwin comes with.

When you run that, does it create a window right away?

7:21 AM

it's more like a terminal

A terminal with a shell prompt?

when i input startx, it will open a bigger window

yes, the first step will open a terminal with a shell prompt

Are you running the ssh inside that terminal?

yes

And you did the "xauth list" there too, and it printed nothing but another shell prompt?

7:24 AM

wow, now after startx, and then run 'xauth list' from the shell, it will print something

mypcname/unix:1 MIT-MAGIC-COOKIE-1 388f2b8389de4263ce9e6b6ac41b2a06
mypcname:1 MIT-MAGIC-COOKIE-1 388f2b8389de4263ce9e6b6ac41b2a06

that's more like what I was hoping for.

but I see you got :1 instead of :0 that's a sign you have two Xservers running at the same time

anyway, after xauth list returns something, the ssh -Y should not complain so much

for 2 xservers, there're indeed 2 X icon on the rightbottom,

the 1st one is when i click the 'cygwin->xwinserver',

the 2nd one appears after i type startx

it seems like the startx command is working better. have you tried the ssh in the terminal created by startx?

yes, i tried, it still return the same error

bash-3.00$ xclock &
[1] 28490
bash-3.00$ Xlib: connection to "mywindowsip:0.0" refused by server
Xlib: No protocol specified

Error: Can't open display: mywindowsip:0.0

did it also say "using fake authentication data" again

7:33 AM

yes

did that ssh client come with cygwin or is it installed separately?

i forgot...it was sometimes ago; but i should be either be cygwin or some package of cygwin when installing cygwin/x

Give it a try with -v added to the ssh command. ssh -v -Y user@host

that will print a bunch of stuff for us to study.

we'll be looking for any mention of X11 or xauth

Warning: No xauth data; using fake authentication data for X11 forwarding.
debug1: Requesting X11 forwarding with authentication spoofing.

that's all i can find with X

OK, that tells me something. At least you didn't get a "debug1: No xauth program."

well this is going to be a pain, but I need you to add another -v to generate even more debugging output.

7:49 AM

another -v?

ssh -v -v -Y user@host?

yeah, that's it

what are we looking for?

looks X11 or xauth are the same..

after the password was entered, something like debug2: x11_get_proto: xauth list :0.0 2>/dev/null

debug2: x11_get_proto: /usr/bin/xauth list :0.0 2>/dev/null

debug1: channel 0: new [client-session]
debug2: channel 0: send open
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug2: callback start
debug2: x11_get_proto: /usr/bin/xauth list :0.0 2>/dev/null
Warning: No xauth data; using fake authentication data for X11 forwarding.
debug1: Requesting X11 forwarding with authentication spoofing.
debug2: channel 0: request x11-req confirm 0
debug2: client_session2_setup: id 0
debug2: fd 3 setting TCP_NODELAY
debug2: channel 0: request pty-req confirm 1

are you still in a terminal where "xauth list" is showing something?

7:56 AM

yes

if i run this on unix, it will display several items

i mean, after ssh to the unix host

yeah, but you need it to work on the cygwin side, that's where your ssh client is

just tried, it will list 2 items

I think it's strange that the DISPLAY on the unix side is cygwin:0.0 - have you been manually setting a DISPLAY variable?

in unix side?

or in cygwin before ssh?

in cygwin shell, $ echo $DISPLAY
:0.0

on unix side,

echo $DISPLAY
windowsxpip:0.0

It's weird because normally ssh creates DISPLAY variables starting with 10. And it should be localhost.

8:08 AM

do you mean unix side?

yeah, on the unix side within the ssh session

thx

that DISPLAY variable is trying to connect from the unix box to the cygwin X server without going through the ssh forwarding.

i've fixed it by your help

wha?

you had a manual DISPLAY setting somewhere overriding the one that ssh created?

8:10 AM

yes, sometime ago, i added export DISPLAY=mywindowsip:0.0 in my shell rc file

I really should have picked that out sooner

so this was executed everytime when i ssh to the shell

really thanks to you

for spending such a long time with me

I'll go back to the question page and put the official answer in

thx. I'm wondering how I can do something back to you?

no need, you were a good cooperative debugging partner, it was fun

last day (14 days later) »

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Jul '1230

Discussion between Alan Curry and het…

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cygwin xauth xserver

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