# Test IPv6 Connections ## Linux On Linux, log into your instance and execute the following command: ```bash ping6 2001:4860:4860::8888 ``` Output: ```bash PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes 64 bytes from 2001:4860:4860::8888: icmp_seq=1 ttl=51 time=4.60 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=2 ttl=51 time=4.08 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=3 ttl=51 time=4.13 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=4 ttl=51 time=4.12 ms ^C --- 2001:4860:4860::8888 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3004ms rtt min/avg/max/mdev = 4.085/4.237/4.607/0.214 ms ``` If you get an error, check if the IPv6 address is correctly assigned on the first interface: ```bash ip -6 a l dev eth0 ``` Output: ```bash 2: eth0: mtu 1500 state UP qlen 1000 inet6 2a04:c43:c00:12f:491:58ff:fe00:79/64 scope global mngtmpaddr dynamic valid_lft 86360sec preferred_lft 14360sec inet6 fe80::480:58ff:fe00:79/64 scope link valid_lft forever preferred_lft forever ``` In addition to the `fe80::` address prefix, you should get an address starting with `2a04::`. If you do not have the `fe80::` address prefix, IPv6 is disabled on your system. You can enable it with: ```bash sysctl -w net.ipv6.conf.all.disable_ipv6=0` ``` If you do not have the `2a04::` address prefix, the auto-configuration mechanism failed. This might be because of a locally configured firewall, or because IPv6 auto-configuration has been disabled. You can enable IPv6 auto-configuration with: ```bash sysctl net.ipv6.conf.eth0.autoconf=1 ``` If the addresses are present, check if: - you do not have a local firewall (check `ip6tables-save`), - you are not using egress rules in your security groups, and - you do not use privacy extensions (check `sysctl net.ipv6.conf.eth0.use_tempaddr`, it should be 0). ## Windows On Windows, you need to disable privacy extensions. You can disable privacy extensions by issuing the following commands in an administrative PowerShell session: ```powershell Set-NetIPv6Protocol -RandomizeIdentifiers Disabled Set-NetIPv6Protocol -UseTemporaryAddresses Disabled ``` Then, you can test with `ping6`: ```powershell ping6 2001:4860:4860::8888 ``` Output: ```powershell Pinging 2001:4860:4860::8888 with 32 bytes of data: Reply from 2001:4860:4860::8888: time<1ms Reply from 2001:4860:4860::8888: time<1ms Reply from 2001:4860:4860::8888: time=1ms Reply from 2001:4860:4860::8888: time=1ms Ping statistics for 2001:4860:4860::8888: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 1ms, Average = 0ms ``` If this does not work, use `ipconfig /all` to check if you have an IPv6 address: ```powershell ipconfig /all ``` Output: ```powershell […] Ethernet adapter Ethernet: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter Physical Address. . . . . . . . . : 06-6B-EA-00-00-36 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : 2a04:c46:c00:12f:46b:eaff:fe00:36(Preferred) Link-local IPv6 Address . . . . . : fe80::46b:eaff:fe00:36%5(Preferred) IPv4 Address. . . . . . . . . . . : 89.145.160.49(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.252.0 Lease Obtained. . . . . . . . . . : mardi, 17 avril 2018 14:10:14 Lease Expires . . . . . . . . . . : vendredi, 24 mai 2154 20:45:03 Default Gateway . . . . . . . . . : fe80::fc6b:eaff:fe00:36%5 89.145.160.1 DHCP Server . . . . . . . . . . . : 89.145.160.1 DHCPv6 IAID . . . . . . . . . . . : 55727104 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-22-67-9C-42-06-6B-EA-00-00-36 DNS Servers . . . . . . . . . . . : 89.145.160.136 89.145.161.109 185.150.8.225 NetBIOS over Tcpip. . . . . . . . : Enabled ``` Also check if you got a default route: ```powershell route print ::/0 ``` ```powershell […] IPv6 Route Table =========================================================================== Active Routes: If Metric Network Destination Gateway 5 271 ::/0 fe80::fc6b:eaff:fe00:36 =========================================================================== Persistent Routes: None ``` ## OpenBSD On OpenBSD, you need to disable Semantically Opaque Interface Identifiers and privacy extensions. Add the following lines in `/etc/hostname.vio0`: ```bash -soii -autoconfprivacy ``` As of OpenBSD version 6.9 `autoconfprivacy` option has been deprecated and replaced by `temporary`. Make sure you specify `inet6 autoconf` options in `/etc/hostname.vio0` in a single line: ```bash inet6 autoconf -soii -temporary ``` Then, use `sh /etc/netstart vio0` to reload the configuration. You can test if it works correctly with `ping6`: ```bash ping6 2001:4860:4860::8888 ``` Output: ```bash PING 2001:4860:4860::8888 (2001:4860:4860::8888): 56 data bytes 64 bytes from 2001:4860:4860::8888: icmp_seq=0 hlim=61 time=1.296 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=1 hlim=61 time=1.294 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=2 hlim=61 time=1.218 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=3 hlim=61 time=1.171 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=4 hlim=61 time=1.345 ms 64 bytes from 2001:4860:4860::8888: icmp_seq=5 hlim=61 time=1.117 ms ^C --- 2001:4860:4860::8888 ping statistics --- 6 packets transmitted, 6 packets received, 0.0% packet loss round-trip min/avg/max/std-dev = 1.117/1.240/1.345/0.079 ms ``` If this does not work, check that you got an IPv6 with `ifconfig`: ```bash ifconfig vio0 ``` Output: ```bash vio0: flags=648843 mtu 1500 lladdr 06:6b:ea:00:00:36 index 1 priority 0 llprio 3 groups: egress media: Ethernet autoselect status: active inet 89.145.160.49 netmask 0xfffffc00 broadcast 89.145.163.255 inet6 fe80::46b:eaff:fe00:36%vio0 prefixlen 64 scopeid 0x1 inet6 2a04:c46:c00:12f:46b:eaff:fe00:36 prefixlen 64 autoconf pltime 14350 vltime 86350 ``` Also, check if you got the default gateway: ```bash route -n show | grep default | tail -1 ``` Output: ```bash default fe80::fc6b:eaff:fe00:36%vio0 UGS 0 3 - 56 vio0 ``` ## Fedora CoreOS On Fedora CoreOS (FCOS), Network manager default configuration is set to `stable-privacy`. `Eui64` mode is required to get IPv6 operational. It can be switched using the following command: ```bash nmcli connection modify 'Wired connection 1' ipv6.addr-gen-mode default-or-eui64 ``` A reboot is required for the change to take effect.