Ho installato per prova su un ubuntu 18 virtualizzato su virtualbox openvpn.
nell'immagine su virtualbox ho impostato un ip statico.
Uso una rete con un interfaccoa nat e hostonly.
sull interfaccia hostonly ho impostato l'ip statico cosi:
codice:
[email protected]:~$ ifconfig
as0t0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 172.27.224.1  netmask 255.255.248.0  destination 172.27.224.1
        inet6 fe80::2a55:332a:366b:1df7  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 11  bytes 528 (528.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

as0t1: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 172.27.232.1  netmask 255.255.248.0  destination 172.27.232.1
        inet6 fe80::c3fb:59e0:fe22:83f9  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 11  bytes 528 (528.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
        inet6 fe80::42:f1ff:fe9e:cfbe  prefixlen 64  scopeid 0x20<link>
        ether 02:42:f1:9e:cf:be  txqueuelen 0  (Ethernet)
        RX packets 162  bytes 34590 (34.5 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 108  bytes 25246 (25.2 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.2.15  netmask 255.255.255.0  broadcast 10.0.2.255
        inet6 fe80::a00:27ff:fe0f:8739  prefixlen 64  scopeid 0x20<link>
        ether 08:00:27:0f:87:39  txqueuelen 1000  (Ethernet)
        RX packets 135995  bytes 162125578 (162.1 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 20361  bytes 1375401 (1.3 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.56.1  netmask 255.255.255.0  broadcast 192.168.56.255
        inet6 fe80::a00:27ff:fe99:f2c7  prefixlen 64  scopeid 0x20<link>
        ether 08:00:27:99:f2:c7  txqueuelen 1000  (Ethernet)
        RX packets 548  bytes 93868 (93.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1905  bytes 2917584 (2.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 220  bytes 19444 (19.4 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 220  bytes 19444 (19.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

vethab88403: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::acd1:62ff:fe8e:84f1  prefixlen 64  scopeid 0x20<link>
        ether ae:d1:62:8e:84:f1  txqueuelen 0  (Ethernet)
        RX packets 162  bytes 36858 (36.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 124  bytes 26462 (26.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
ora: ho configurato openvpn su virtualbox.
adesso se imposto sull ubuntu host (il pc che contiene la virtualbox) la connessione a vpn è tutto ok.
https://ibb.co/pJ6p231
i problemi sono:
1)internet quando la vpn è connessa va lentissimo e non capisco perchè
2)adesso che la vpn tra l'host e il guest è in funzione, come faccio a condividere cartelle , vedere hd eccc...?devo creare una rete linux(l'host è un ubuntu 20)?e questa è la cosa principale che non ho capito
3)se digito ifconfig dopo che la vpn è connessa vedo un tun0 è il tunnel criptato?

chiedo scusa se a voi vi sembrano banalità o sciocchezze ma voglio imparare.
ciao.