F21 - Refreshing DNCP lease on ethernet

[Robert Moskowitz]

I am using ethernet to connect to a firewall I am configuring.  My 
initial connection did not have any dhcp config info (because I had not 
configured the server) like DNS servers and the like.  I have since 
configed the firewall, but cannot get this information to my system.  I 
tried:

ifdown p6p1; ifup p6p1

And that did not refresh the dhcp information.  I deleted the lease on 
the firewall and bounced the ethernet with no changes. /etc/resolv still 
does not have my DNS server addresses.

With WiFi, I would have turned off the radio, turned it back on, 
connected to my SSID and (normally) gotten the new lease info.

BTW, this is a F21/Gnome setup (have not found the time to upgrade this 
notebook to F22...)