How to fix internet issues on virtualbox guest VMs with NAT
1) Identify the issue
(base) [root@localhost ~]# ping www.google.com
^C
(base) [root@localhost ~]#
2) Quick fix is to edit /etc/resolv.conf as shown below..
Actual:
(base) [root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 10.0.2.3
(base) [root@localhost ~]#
Replace it as shown below:
(base) [root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 8.8.8.8
nameserver 1.1.1.1
(base) [root@localhost ~]#
3) Test the fix
(base) [root@localhost ~]# ping google.com
PING google.com (192.178.223.113) 56(84) bytes of data.
64 bytes from yulhrs-in-f113.1e100.net (192.178.223.113): icmp_seq=1 ttl=105 time=7.23 ms
^C
--- google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 7.227/7.227/7.227/0.000 ms
(base) [root@localhost ~]#
4) Make it persistent across restarts
(base) [root@localhost ~]# nmcli conn show
NAME UUID TYPE DEVICE
eth0 a313d9c0-8613-468f-a354-e892fe7e3817 ethernet eth0
System eth1 9c92fad9-6ecb-3e6c-eb4d-8a47c6f50c04 ethernet eth1
lo a12a3dcb-af7a-4987-b824-7a9fb48c3b0b loopback lo
br-7ca1385b85f2 b51a597f-e9c5-43f1-95bf-68f5ed335192 bridge br-7ca1385b85f2
docker0 21fd4af2-d44f-4931-9b1a-985fa92769eb bridge docker0
(base) [root@localhost ~]#
5) Look for the connection supplying dns
(base) [root@localhost ~]# nmcli dev show | grep DNS
IP4.DNS[1]: 10.0.2.3
(base) [root@localhost ~]#
6) Examine the below network manager conf file
cat /etc/NetworkManager/system-connections/eth0.nmconnection
[connection]
id=eth0
uuid=a313d9c0-8613-468f-a354-e892fe7e3817
type=ethernet
autoconnect-priority=-100
autoconnect-retries=1
interface-name=eth0
multi-connect=1
timestamp=1756384622
wait-device-timeout=60000
[ethernet]
[ipv4]
method=auto
[ipv6]
addr-gen-mode=eui64
method=auto
[proxy]
[user]
org.freedesktop.NetworkManager.origin=nm-initrd-generator
(base) [root@localhost ~]#
7) Look for dns related setting
grep -i dns /etc/NetworkManager/system-connections/eth0.nmconnection
8) Add the nameservers now which we added above
nmcli con mod "eth0" ipv4.dns "8.8.8.8,1.1.1.1"
nmcli con mod "eth0" ipv4.ignore-auto-dns yes
nmcli con up "eth0"
Actual:
(base) [root@localhost ~]# grep -i dns /etc/NetworkManager/system-connections/eth0.nmconnection
(base) [root@localhost ~]# nmcli con mod "eth0" ipv4.dns "8.8.8.8,1.1.1.1"
(base) [root@localhost ~]# nmcli con mod "eth0" ipv4.ignore-auto-dns yes
(base) [root@localhost ~]# nmcli con up "eth0"
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/6)
(base) [root@localhost ~]#
9) Check if ip is up
(base) [root@localhost ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 08:00:27:dc:3b:82 brd ff:ff:ff:ff:ff:ff
altname enp0s3
inet 10.0.2.15/24 brd 10.0.2.255 scope global dynamic noprefixroute eth0
valid_lft 86398sec preferred_lft 86398sec
inet6 fe80::a00:27ff:fedc:3b82/64 scope link noprefixroute
valid_lft forever preferred_lft forever
10) Verify the file /etc/NetworkManager/system-connections/eth0.nmconnection
(base) [root@localhost ~]# cat /etc/NetworkManager/system-connections/eth0.nmconnection
[connection]
id=eth0
uuid=a313d9c0-8613-468f-a354-e892fe7e3817
type=ethernet
autoconnect-priority=-100
autoconnect-retries=1
interface-name=eth0
multi-connect=1
timestamp=1769037930
wait-device-timeout=60000
[ethernet]
[ipv4]
dns=8.8.8.8;1.1.1.1;
ignore-auto-dns=true
method=auto
[ipv6]
addr-gen-mode=eui64
method=auto
[proxy]
[user]
org.freedesktop.NetworkManager.origin=nm-initrd-generator
(base) [root@localhost ~]#
11) Verify further setup and test internet
(base) [root@localhost ~]# nmcli dev show | grep DNS
IP4.DNS[1]: 8.8.8.8
IP4.DNS[2]: 1.1.1.1
(base) [root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 8.8.8.8
nameserver 1.1.1.1
(base) [root@localhost ~]#
12) check internet
(base) [root@localhost ~]# ping google.com
PING google.com (192.178.223.113) 56(84) bytes of data.
64 bytes from yulhrs-in-f113.1e100.net (192.178.223.113): icmp_seq=1 ttl=105 time=7.24 ms
^C
--- google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 7.244/7.244/7.244/0.000 ms
(base) [root@localhost ~]#
