OpenVPN: IPv6 /128 single client
sumber: https://www.ostechnix.com/easiest-way-install-configure-openvpn-server-linux/
Topology
CLIENT 1 ------- HOST A ---------------- HOST B --------- CLIENT 2
ovpn server ovpn client
2345::1/64
Host A akan berfungsi sebagai OpenVPN Server.
OS : Ubuntu 18.04 IP : 192.168.0.239/24 (IP public) hostname : vpnserver
Host B akan berfungsi sebagai OpenVPN client
OS : Ubuntu 18.04
Konfigurasi OpenVPN Client
Pastikan openvpn terinstalsi
sudo su apt install openssh-server openvpn
Edit /etc/hosts isi dengan nama OpenVPN server
192.168.0.239 vpnserver
Jalankan OpenVPN client
cd ~ sudo su openvpn --config client.ovpn
Akan keluar kira-kira
.. .. Sun Mar 10 18:58:24 2019 Data Channel: using negotiated cipher 'AES-256-GCM' Sun Mar 10 18:58:24 2019 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key Sun Mar 10 18:58:24 2019 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key Sun Mar 10 18:58:24 2019 ROUTE_GATEWAY 192.168.0.222/255.255.255.0 IFACE=enp0s3 HWADDR=08:00:27:3f:39:70 Sun Mar 10 18:58:24 2019 GDG6: remote_host_ipv6=n/a Sun Mar 10 18:58:24 2019 ROUTE6: default_gateway=UNDEF Sun Mar 10 18:58:24 2019 TUN/TAP device tun0 opened Sun Mar 10 18:58:24 2019 TUN/TAP TX queue length set to 100 Sun Mar 10 18:58:24 2019 do_ifconfig, tt->did_ifconfig_ipv6_setup=1 Sun Mar 10 18:58:24 2019 /sbin/ip link set dev tun0 up mtu 1500 Sun Mar 10 18:58:24 2019 /sbin/ip addr add dev tun0 10.8.0.2/24 broadcast 10.8.0.255 Sun Mar 10 18:58:24 2019 /sbin/ip -6 addr add 2345::1000/64 dev tun0 Sun Mar 10 18:58:24 2019 /sbin/ip route add 192.168.0.105/32 dev enp0s3 Sun Mar 10 18:58:24 2019 /sbin/ip route add 0.0.0.0/1 via 10.8.0.1 Sun Mar 10 18:58:24 2019 /sbin/ip route add 128.0.0.0/1 via 10.8.0.1 Sun Mar 10 18:58:24 2019 add_route_ipv6(2000::/3 -> 2345::1 metric -1) dev tun0 Sun Mar 10 18:58:24 2019 /sbin/ip -6 route add 2000::/3 dev tun0 Sun Mar 10 18:58:24 2019 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this Sun Mar 10 18:58:24 2019 Initialization Sequence Completed
Perhatikan di bagian agak bawah terlihat ada beberapa setup IPv6. Selanjutnya cek Interface, akan muncul tun0 yang ada IPv6-nya
ifconfig
tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.8.0.2 netmask 255.255.255.0 destination 10.8.0.2
inet6 fe80::8872:a14c:5076:40b5 prefixlen 64 scopeid 0x20<link>
inet6 2345::1000 prefixlen 64 scopeid 0x0<global>
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 100 (UNSPEC)
RX packets 4837 bytes 5672472 (5.6 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3898 bytes 324037 (324.0 KB)
TX errors 0 dropped 106 overruns 0 carrier 0 collisions 0
Perhatikan IPv4 address keluarga 10.8.0.0/16 dan ada IPv6 address sesuai dengan settingan yang ada di OpenVPN Server. Selanjutnya cek sambungan menggunakan IPv6,
ping -I tun0 2345::1
Sample output:
PING 2345::1(2345::1) from 2345::1000 tun0: 56 data bytes 64 bytes from 2345::1: icmp_seq=1 ttl=64 time=0.610 ms 64 bytes from 2345::1: icmp_seq=2 ttl=64 time=0.692 ms 64 bytes from 2345::1: icmp_seq=3 ttl=64 time=0.582 ms 64 bytes from 2345::1: icmp_seq=4 ttl=64 time=0.603 ms 64 bytes from 2345::1: icmp_seq=5 ttl=64 time=0.625 ms 64 bytes from 2345::1: icmp_seq=6 ttl=64 time=0.625 ms ^C --- 2345::1 ping statistics --- 6 packets transmitted, 6 received, 0% packet loss, time 5110ms rtt min/avg/max/mdev = 0.582/0.622/0.692/0.046 ms
Cek routing
ip -6 route show
Pastikan ada routing ke IPv6 address
2345::/64 dev enp0s3 proto kernel metric 100 pref medium 2345::/64 dev tun0 proto kernel metric 256 pref medium 2000::/3 dev tun0 metric 1024 pref medium fe80::/64 dev enp0s3 proto kernel metric 256 pref medium fe80::/64 dev tun0 proto kernel metric 256 pref medium