Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [xdmcp]

X Display Manager Control Protocol

The X Display Manager Control Protocol (XDMCP) is a TCP/UDP based protocol for connecting to X11 display manager like XDM. It was originally specified in 1989 and lacks security features like e.g. connection encryption.

21 questions
5
votes
1 answer

where can I find the MIT-MAGIC-COOKIE in the user side?

While digging into X Windows or X11 stuff I found that X display uses MIT-MAGIC-COOKIE to allow client-server to exchange display data. One thing I don't understand is that I am able to locate and view the MIT-MAGIC-COOKIE in the server(Xclient)…
kwagjj
  • 2,309
  • 6
  • 22
  • 29
4
votes
2 answers

How to configure fonts on a remote X connection (XDMCP vs. ssh)?

Connecting to a remote Solaris 10 system over X11 I observe inconsistent behavior regarding the used fonts. I am connecting from a Cygwin/X system. When I connect using ssh forwarding like this $ ssh -Y mymachine.example.org fonts work as expected,…
maxschlepzig
  • 56,316
  • 50
  • 205
  • 279
3
votes
2 answers

Why do I need XDMCP to start a remote X session over SSH?

I'm trying to set up a remote desktop connection to access my desktop PC from my laptop (both running Trisquel) over wifi. I've tried VNC and it was terribly slow, so I'm looking at alternative options. What I would ideally like to do is to start a…
Time4Tea
  • 2,288
  • 5
  • 23
  • 54
3
votes
0 answers

XDMCP "maximum number of open sessions from your host reached" but no session is active

I'm using XDMCP to access CentOS 6 hosts from Cygwin/X. Everything works fine, but every now and then attempting to connect results in the error message: XDMCP fatal error: Session declined maximum number of open sessions from your host…
Nicola Musatti
  • 131
  • 4
3
votes
1 answer

Configure XDM to accept remote logins

How can I configure XDM server to accept remote X login and works as X server, which Configuration should be done on the clients if they want to connect to this X server?
Shahram Pezeshki
  • 111
  • 3
  • 7
2
votes
1 answer

How do I avoid colour channel issues with 24-bit colour remote X11 with older Solaris?

When using CDE on older Solaris systems (2.5.x) remotely using XDMCP with TrueColor visuals, on-screen pixmaps are missing the blue channel and have the red and green channels swapped. This means that white appears as yellow, green as red, red as…
rakslice
  • 1,147
  • 2
  • 11
  • 17
2
votes
1 answer

Export Display is not working on Ubuntu Gnome (gmd3)

When I try to export the remote display I do: In my Ubuntu 17.04: xhost + access control disabled, clients can connect from any host Then I make the connection to the server: ssh user@server Once in the server get this error: user@server:~$…
bLuEdDy
  • 89
  • 1
  • 2
  • 7
2
votes
1 answer

How to resolve black screen issue with Xnest/XDMCP

My environment consist of a Ubuntu 14.04 LTS VM. This is acting as the Xnest server on socket :2 and port 6002 (as seen by netstat). I'm running the Xnest as client on a Fedora 20 VM. The Ubuntu system runs Xnest 2:1:15:1. My Xnest version on Fedora…
user53029
  • 2,725
  • 8
  • 40
  • 65
2
votes
1 answer

how to 'forward' x display data?

this is my situation: there are three computers lab server (CentOS) lab personal computer(window s7) personal laptop(ubuntu) since the lab server only allowed ip address of my desktop at the lab, I was unable to establish a direct remote…
kwagjj
  • 2,309
  • 6
  • 22
  • 29
1
vote
1 answer

Opening session via XDMCP to GDM

I have a RHEL6 server which we connect via XDMCP. If I start xdm (xdm &) it works but the login screen is the old xdm simple login and not gdm. Our RHEL5 servers connect to gdm just fine. The problem is that GDM isn't running. When I try to launch…
Jeight
  • 2,555
  • 3
  • 19
  • 28
1
vote
0 answers

XDMCP locally using Unix sockets

Is there any way to start a XDMCP session, say with Xephyr in LightDM, locally through Unix Sockets instead of IP? For performance I was wondering if, somehow, I can avoid any network stack working with Xephyr and the XDMCP server in the same…
igorkattar
  • 71
  • 1
  • 5
1
vote
0 answers

Can XDMCP be encrypted with RSA or AES? Can XDMCP be forwarded over SSL or TLS?

I know XDMCP cannot be forwarded over SSH because XDMCP uses UDP and SSH uses TCP. Can XDMCP be forwarded over SSL or TLS instead? XDMCP is not encrypted by default. Can AES or RSA be added to XDMCP connection?
Jonathan Dahlin
  • 11
  • 3
1
vote
1 answer

How to use XDMCP when server and client are behind two NAT?

The network structure is: Server -> NAT router1 -> switch <- NAT router2 <- Client The part I cannot solve is that, after xserver connects to 177/udp of xdm, xdm connects back to xserver, say 6001/tcp. So the server network does not know how to…
Magicloud
  • 733
  • 1
  • 6
  • 17
0
votes
0 answers

Connecting via VCXSRV leads to a blank screen

When trying to use vcxsrv on my laptop I am unable to remotely connect to a Linux system. I just get a blank screen during the remote connection attempt. I have captured the log file as shown below: Welcome to the VcXsrv X Server Vendor: The VcXsrv…
hymcode
  • 19
  • 5
0
votes
0 answers

Allow multiple XDMCP sessions (local and remote) for the same user

Currently, on our CentOS 7 machines, we are able to log in to the usera account on the physical CentOS machine and also access the same usera account remotely via XDMCP using XMing. I performed the same setup steps from our CentOS 7 machine on our…
hymcode
  • 19
  • 5
1
2