Comment 19 for bug 279262

The way I worked around this was to change [ifupdown] manage=false to true in the interfaces file. I then created a new connection "eth1" within networkmanager copying the MAC address from the ifupdown (eth1) entry or which ever one you are using to the new connection. I was able to make it a static connection and it was also editable. My issue now is that when I boot it defaults to the ifupdown (eth1) connection where I can't edit it to add the DNS server. I can now click the nm icon and select "eth1" and my new connection works with everything. I have tried to delete the ifupdown (eth1) entry in nm and get Removing connection failed: ifupdown - connection delete not supported (read-only).. Hope this helps some of you until a fix.