Network Settings problem

Hi
I was playing around with my network settings in yast and lost my internet connection.
I was in “Network card setup” and added alias, address & subnet to the ethernet controller. This stopped the internet working - however when deleting what I added, it removes it- but not permanently. If I go into it again, the entry is still there.
I would like to know how to get rid of the entries that I added, and
Is there a command to “tunnel” to the internet like yast does when you set up your computer