Install second network interface on virtualized Ubuntu Server

I've just installed the latest Ubuntu 16.04 on a VirtualBox machine. I'd like to have two different network interfaces:

1. the first one to access the guest machine from the host using ssh; for this reason, I've installed the Host-only Adapter as adapter 1
2. the second one to be able to connect to internet from the host machine, so I've installed a basic NAT as adapter 2

However, even if both the network adapters are correctly identified, only the first one is accessible.

$ ls /sys/class/net/
enp0s3 enp0s8 lo
$ ifconfig
enp0s3 Link encap:Ethernet HWaddr 08:00:27:47:52:7b inet addr:192.168.56.101 Bcast:192.168.56.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe47:527b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:399 errors:0 dropped:0 overruns:0 frame:0 TX packets:246 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:44031 (44.0 KB) TX bytes:75269 (75.2 KB)
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:92 errors:0 dropped:0 overruns:0 frame:0 TX packets:92 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1 RX bytes:40721 (40.7 KB) TX bytes:40721 (40.7 KB)

How can I make the system recognize the second card also?

2 Answers

I've solved the problem adding

# The secondary network interface
auto enp0s8
iface enp0s8 inet dhcp

to /etc/network/interfaces

(Get the new interface name using ifconfig -a)

and restarting the network using sudo service networking restart.

Now, here is the result of

$ ifconfig enp0s3 Link encap:Ethernet HWaddr 08:00:27:47:52:7b inet addr:192.168.56.101 Bcast:192.168.56.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe47:527b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:6334 errors:0 dropped:0 overruns:0 frame:0 TX packets:7656 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2741526 (2.7 MB) TX bytes:10824219 (10.8 MB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:3e:1e:bf inet addr:10.0.3.15 Bcast:10.0.3.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe3e:1ebf/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:8 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1730 (1.7 KB) TX bytes:1882 (1.8 KB)
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2143 errors:0 dropped:0 overruns:0 frame:0 TX packets:2143 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1 RX bytes:443165 (443.1 KB) TX bytes:443165 (443.1 KB)

if it's on an updated Ubuntu server that doesn't use ifup, enter your new config into the /etc/netplan/50-cloud-init.yaml instead:

network: ethernets: enp0s3: dhcp4: true enp0s8: dhcp4: true
version: 2

and then run:

netplan apply

then it should pop up!