How to enable internet access of CentOS 7 on VirtualBox13 Jun 2019
I was setting up a CentOS 7 virtual machine using VirtualBox to replicate an existing setup when I discovered that I cannot access the internet even though my VM was setup to use a bridged adapter.
Diagnosing the problem
I wanted to know the status of network interfaces on my virtual machine so I execute the nmcli command.
$ nmcli enp0s3: disconnected "Intel 82540EM" 1 connection available ethernet (e1000), 08:00:27:A7:B4:52, autoconnect, hw, mtu 1500 lo: unmanaged "lo" loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536 Use "nmcli device show" to get complete information about known devices and "nmcli connection show" to get an overview on active connection profiles. Consult nmcli(1) and nmcli-examples(5) manual pages for complete usage details.
The command shows that enp0s3 is diconnected so I checked its network configuration script.
$ cat /etc/sysconfig/network-scripts/ifcfg-enp0s3 TYPE=Ethernet PROXY_METHOD=none BROWSER_ONLY=no BOOTPROTO=dhcp DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=enp0s3 UUID=1056c9af-dc47-429b-958c-d0e83b99d60f DEVICE=enp0s3 ONBOOT=no
I found out that the reason I have no access to the internet is because it is not configured to be activated on boot. The last line ONBOOT=no means that this network interface won’t be activated on startup.
Configuring the network interface
To resolve this I opened a text editor to edit the network configuration and changed the last line to ONBOOT=yes.
sudo vi /etc/sysconfig/network-scripts/ifcfg-enp0s3
I have to restart the network and apply the changes.
sudo systemctl restart network.service
Now if I check the interface, it would show that it is connected.
$ nmcli enp0s3: connected to enp0s3 "Intel 82540EM" ethernet (e1000), 08:00:27:A7:B4:52, hw, mtu 1500 ip4 default inet4 10.0.2.15/24 route4 0.0.0.0/0 route4 10.0.2.0/24 inet6 fe80::f63f:8611:805b:579d/64 route6 fe80::/64 route6 ff00::/8 lo: unmanaged "lo" loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536 DNS configuration: servers: 18.104.22.168 22.214.171.124 domains: apple.com interface: enp0s3 Use "nmcli device show" to get complete information about known devices and "nmcli connection show" to get an overview on active connection profiles. Consult nmcli(1) and nmcli-examples(5) manual pages for complete usage details.
Testing access to the internet
Now to check if my virtual machine has access to the internet.
$ ping google.com PING google.com (126.96.36.199) 56(84) bytes of data. 64 bytes from 188.8.131.52 (184.108.40.206): icmp_seq=1 ttl=41 time=71.7 ms 64 bytes from 220.127.116.11 (18.104.22.168): icmp_seq=2 ttl=41 time=73.8 ms 64 bytes from 22.214.171.124 (126.96.36.199): icmp_seq=3 ttl=41 time=73.1 ms
The command above shows that my virtual machine can now successfully connect to the internet.