Fix for bug 763.

Try to detect IP address for a host as possible.

VTN Manager will send at most 10 ARP requests to a detected host.

Change-Id: I4356b8d42f91a5901315e75cc5dc69e6fffa322a
Signed-off-by: Shigeru Yasuda <s-yasuda@da.jp.nec.com>
(cherry picked from commit b4e36cfd45765e446c8d97e881d5df50ca002921)