xterm: Xt error: Can't open display: xterm: DISPLAY is not set
Hello, I am completely new to networking/systems. I have been asked to complete an open flow tutorial ( http://www.openflow.org/wk/index.php/OpenFlow_Tutorial ) I have fininshed a part of the tutorial and when i used "ssh -X mininet@192.168.**.*", I was able to log in successfully but when i type in Xterm, it says "xterm: Xt error: Can't open display: xterm: DISPLAY is not set". I have downloaded virtual box, XQuartz and an ovf file as given in teh tutorial. I don't know what the problem is. Can someone please guide me through this? Thank you so much!
MacBook Pro, OS X Mountain Lion (10.8.2)