Ubuntu – How to set static IP address

It would be easier to troubleshoot your problem if you posted the results you are getting when trying to ping an external address (like the Google DNS servers you're using), the current network settings, and your routing table.

/sbin/ifconfig -a
/sbin/route -n

Without knowing more this is a bit of a shot in the dark, but my guesses are that either a) you are not getting a DHCP address on eth0, or b) your gateway settings for eth1 are messing with the default route DHCP assigned.

If you're not getting a DHCP address for eth0, it's probably a misconfiguration in VirtualBox (like getting your adapters backwards).

Either way, you don't need a gateway or DNS settings assigned specifically for eth1 since that will be assigned by DHCP on eth0, so I would remove the gateway, dns-search, and dns-nameservers lines from your config. Your virtual machines will still be able to communicate without a gateway setting if they are on the same network and VirtualBox is set up right.

Edit: To make sure you don't have a gateway on eth1 after a reboot, remove lines from your eth1 block so that it looks like this:

auto eth1
iface eth1 inet static
address 192.168.56.1
netmask 255.255.255.0

When you're done, you won't have any gateway lines in your interfaces file.

First of all you need to understand the type of interfaces and their usage:

1) Host Only: Host only allows you to communicate with host computer only. So you can't use internet or communicate with other VMs.

2) NAT: NAT allows you to communicate with other VMs as well as you can use internet. But you can't access e.g. server running on this VM from other PC on the network.

3) Bridge: Apart from functionality provided by NAT, using Bridge you can access e.g. server running on this VM from other PC on the network.

Hope this helps. Try to test using different interfaces & it'll become more clear.