Ok. First I will enter "root" command in xterm. Then I will simply write command "/etc/network/interfaces", and it gives the following information in xterm; -sh: /etc/network/interfaces: Permission denied Then I will enter "sudo gainroot" command in xterm. Then I will simply write command "/etc/network/interfaces", and it gives the following information in xterm; /bin/sh: /etc/network/interfaces: Permission denied I am quoting the instruction as was written in http://wiki.maemo.org/N900_USB_networking . Please, tell me where I am making the mistake.