Please note that MetaARPA membership is required to run X11 applications
This should be the preferred method of running X. By tunneling through an existing ssh connection, extra firewall ports or port forwarding is not needed. The traffic is also protected by ssh. Note that this tutorial references sverige.freeshell.org however iceland.freeshell.org is also available to MetaARPA members and supports X forwarding.
ssh -X firstname.lastname@example.org.
ssh -o XAuthLocation=`which xauth` -X email@example.com.
The advantage of sending X11 traffic directly is performance (screen updates) should be slightly faster because the data is not encrypted first. The disadvantage of sending X11 traffic directly is the data is not encrypted first. The X client will send the traffic directly to the local X server, so care must be taken to open up firewalls and forward the ports 6000/TCP - 6063/TCP as necessary.
The above methods no longer seem to be working, but you can still use x11 via SSH on the MetaArray. The command to do this is
ssh -Y firstname.lastname@example.org, where userid is your SDF user id.