Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Remote access
PV208 Advanced topics of Linux administration
Zbyněk Ondrák
Faculty of Informatics
Masaryk university
April 17, 2008
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Remote access - overview
* textual and graphical interface
* terminal services
* file system or particular files access
* messaging and other protocols for web, time
synchronization, audio transmission
* database access and manipulation
* mobile systems - wireless internet, bluetooth, infraport
* graphical interface
* window manager of multi-user systems
* desktop sharing - real-time collaboration
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Terminal Services on Thin Client and Protocols
* non-secure connection (no encryption)
* telnet, rlogin - rhosts authorization mechanism,
rsh - rlogin with a command, http, nntp (news), pop3, irc,
ntp, rtp etc.
* file transfer or file system connection - rcp, ftp, nfs, svn
(replacement of cvs), LDAP
* secure connection (with encryption)
* ssh, enabling VPN, https, nntps, pop3s etc.
* file transfer or file system connection - scp, sftp, sfs
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Remote usage of the X Window System
* X forwarding
* transmits remotely started applications to the local X server
* usage: ssh -X (manually via DISPLAY environment
variable), putty on Windows system
* xhost - allows hosts to connect to the X server
* xauth - allows users who know a secret (~/.Xauthority)
* XDMCP (over trusted networks - e.g. VPN in public)
* display manager running on a remote system connects
to the local X server
Windows: Xming acts as the X server
* starts remote window manager after login
* usage: X [local display] -query [host]
* starting X applications (e.g. window manager):
[app] -display [specified display]
* windowed mode - Xnest
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Remote Frame Buffer protocol (RFB)
* relatively simple protocol applicable to X Window System,
Windows and Mac OS X
* Virtual Network Computing (VNC)
* VNC viewers connect to a created VNC server
(Xvnc - based on the X server)
* high level usage: vncserver, vncviewer
* ~/.vnc/xstartup - startup script
(e.g. changing window manager)
* KDE: krfb - desktop sharing on a remote system,
krdc - client
* Apple Remote Desktop in Mac OS X
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
Remote Desktop Protocol (RDP)
* uses 128-bit encryption with RC4, redirection of audio,
local file systems, local printers, local ports and others
* Windows: Terminal Services
* Terminal Server,
Remote Desktop Connection or Terminal Services Client client
(one session per PC is allowed)
* Windows Desktop Sharing - shares entire desktop,
a specific region or a particular application to multiple
clients
* rdesktop - Unix based client utility (tsclient for GUI
frontend, xrdp - based on rdesktop)
Overview Basic tools and protocols X Window System RFB protocol (VNC) RDP (Windows)
References
* http://tldp.org/HOWTO/Remote-X-Apps.html
* http://en.wikipedia.org/wiki/Desktop sharing
* http://en.wikipedia.org/wiki/XDMCP
* http://en.wikipedia.org/wiki/RFB protocol
* http://en.wikipedia.org/wiki/Remote Desktop Protocol
* http://en.wikipedia.org/wiki/Comparison of remote
desktop software