VirtualBox Host Mac not able to connect to VirtualBox Guest Windows 7

Question

I'm running VirtualBox version 5.0.20 on Mac OS El Captain 10.11.3 and guest is Windows 7. I'm trying to establish the connectivity between Host Mac and guest Windows.

For this, I have set up Host Only Network with subnet 192.168.57.* . Host machine has IP 192.168.57.1 and guest has 192.168.57.105 (manually configured). The connectivity works if I have set up only one adapter that is Host Only Network.

But when I add one more adapter NAT for Internet connectivity from Guest Windows 7, the connectivity breaks.

How can I make both NAT and Host Only Network work together ?

Guest Windows IP Configuration:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : *********
   Primary Dns Suffix  . . . . . . . : *****************
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : ******************
                                       Gateway

Ethernet adapter Local Area Connection 3:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Desktop Adapter #2
   Physical Address. . . . . . . . . : 08-00-27-E7-90-64
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::8c17:af04:a3e6:dd98%13(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.57.105(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.57.1
   DHCPv6 IAID . . . . . . . . . . . : 369623079
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1F-76-DD-DD-08-00-27-48-FE-AE

   DNS Servers . . . . . . . . . . . : 192.168.57.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : Gateway
   Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Desktop Adapter
   Physical Address. . . . . . . . . : 08-00-27-48-FE-AE
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::1032:4017:bd44:93c1%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.0.2.15(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Friday, September 23, 2016 7:51:07 PM
   Lease Expires . . . . . . . . . . : Sunday, September 25, 2016 12:42:07 PM
   Default Gateway . . . . . . . . . : 10.0.2.2
   DHCP Server . . . . . . . . . . . : 10.0.2.2
   DHCPv6 IAID . . . . . . . . . . . : 285736999
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1F-76-DD-DD-08-00-27-48-FE-AE

   DNS Servers . . . . . . . . . . . : 192.168.0.1
   NetBIOS over Tcpip. . . . . . . . : Enabled  

Answer 1

Have you try with DHCP server?

•In the VirtualBox graphical user interface, you can configure all these items in the global settings via "File" → "Preferences" → "Network", which lists all host-only networks which are presently in use. Click on the network name and then on the "Edit" button to the right, and you can modify the adapter and DHCP settings.

EDIT:

As you are trying to establish connectivity between host and guest, and need guest to have internet connection, I think your best option is to change from two adapters (host only Adapter and NAT) to only one adapter on bridge adapter mode.

When you setup a "host only Adapter" you need to change your host IP adress to make connection between host and guest possible, this way host and guest loose internet connectivity as host and router are on two different networks.

So if you want to have internet connection on both guest and host, and connect with each other, bridge adapter is what you look for. This way your guest will be seen to your host and the router as another computer attached to it.

Anyhow a look at the manual will not hurt.