Establishing connection with Oracle VM server in virtual box using putty

I have a Oracle VM developer machine (running OEL7.6) running on top of Windows 10. In an attempt to establish connection with the VM server using putty from my desktop, I changed the "Adapter 1" network settings to host only adapter and after starting the machine I was able to get an IP address in eth0, and thereby I was able to establish connection using putty. But after say a few minutes (3 to 4 minutes) I am losing the connection with the VM server, and when I check the eth0 configuration, I see some strange address i.e. "08:00:27:ec:1d:e8" getting reported.

After changing adapter 1 to host only adapter.

        inet 192.168.56.101 netmask 255.255.255.0 broadcast

192.168.56.255<<<<<<<<<<<<<<<<<<<<<<<<< IP address reflecting
        ether 08:00:27:ec:1d:e8  txqueuelen 1000  (Ethernet)
        RX packets 17  bytes 2352 (2.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 22  bytes 3503 (3.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

After few minutes

        ether 08:00:27:ec:1d:e8 txqueuelen 1000

 (Ethernet)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
        RX packets 681  bytes 61970 (60.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 405  bytes 75946 (74.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root_at_localhost ~]# service network restart
Restarting network (via systemctl): Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.

                                                           [FAILED]