ipv6 issue 2a07:a8c1::

Hi, 

there is currently since today morning from France some ipv6 secondary dns issue (2a07:a8c1::).

The diag tool (https://nextdns.io/diag) also have issues with ipv6 connectivity detection (Testing IPv6 connectivity available: false) .

# sh -c 'sh -c "$(curl -s https://nextdns.io/diag)"'

Welcome to NextDNS network diagnostic tool.

This tool will download a small binary to capture latency and routing information
regarding the connectivity of your network with NextDNS. In order to perform a
traceroute, root permission is required. You may therefore be asked to provide
your password for sudo.

The source code of this tool is available at https://github.com/nextdns/diag

Do you want to continue? (press enter to accept)
Testing IPv6 connectivity

  available: false
Fetching https://test.nextdns.io
  status: ok
  client: 2a01:cb15:3e4:xx::xxxx
  protocol: UDP
  dest IP:
  server: netbarista-par-1
Fetching PoP name for ultra low latency primary IPv4 (ipv4.dns1.nextdns.io)
  virtua-par: 13.029ms
Fetching PoP name for ultra low latency secondary IPv4 (ipv4.dns2.nextdns.io)
  netbarista-par: 13.001ms
Fetching PoP name for anycast primary IPv4 (45.90.28.0)
....

# ping 2a07:a8c1::
PING 2a07:a8c1:: (2a07:a8c1::) 56 data bytes
64 bytes from 2a07:a8c1::: icmp_seq=1 ttl=53 time=123 ms
64 bytes from 2a07:a8c1::: icmp_seq=2 ttl=53 time=123 ms
64 bytes from 2a07:a8c1::: icmp_seq=3 ttl=53 time=49.6 ms
64 bytes from 2a07:a8c1::: icmp_seq=4 ttl=53 time=123 ms
64 bytes from 2a07:a8c1::: icmp_seq=5 ttl=53 time=123 ms
64 bytes from 2a07:a8c1::: icmp_seq=6 ttl=53 time=11.9 ms
64 bytes from 2a07:a8c1::: icmp_seq=7 ttl=53 time=123 ms
^C
--- 2a07:a8c1:: ping statistics ---
7 packets transmitted, 7 received, 0% packet loss, time 6008ms
rtt min/avg/max/mdev = 11.882/96.809/123.347/42.975 ms
[19:30:22]root@daneel:~ # ping 2a07:a8c0::
PING 2a07:a8c0:: (2a07:a8c0::) 56 data bytes
64 bytes from 2a07:a8c0::: icmp_seq=1 ttl=50 time=12.0 ms
64 bytes from 2a07:a8c0::: icmp_seq=2 ttl=50 time=12.2 ms
64 bytes from 2a07:a8c0::: icmp_seq=3 ttl=50 time=11.8 ms
64 bytes from 2a07:a8c0::: icmp_seq=4 ttl=50 time=11.9 ms
64 bytes from 2a07:a8c0::: icmp_seq=5 ttl=50 time=18.6 ms
64 bytes from 2a07:a8c0::: icmp_seq=6 ttl=50 time=12.4 ms
^C
--- 2a07:a8c0:: ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5007ms
rtt min/avg/max/mdev = 11.810/13.146/18.563/2.429 ms

# traceroute -I 2a07:a8c1::
traceroute to 2a07:a8c1:: (2a07:a8c1::), 30 hops max, 80 byte packets
 1  router1.xxxx (fd11:0:0:2::7)  0.097 ms  0.113 ms  0.108 ms
 2  * * *
 3  2a01:cfc0:200:8000:193:252:102:49 (2a01:cfc0:200:8000:193:252:102:49)  11.562 ms * *
 4  * * 2a01:cfc4:0:1b00::13 (2a01:cfc4:0:1b00::13)  11.163 ms
 5  * * *
 6  dns2.nextdns.io (2a07:a8c1::)  123.249 ms *  122.821 ms

# traceroute -I 2a07:a8c0::
traceroute to 2a07:a8c0:: (2a07:a8c0::), 30 hops max, 80 byte packets
 1  router1.xxxx (fd11:0:0:2::7)  0.144 ms  0.111 ms  0.153 ms
 2  * * *
 3  2a01:cfc0:200:8000:193:252:102:49 (2a01:cfc0:200:8000:193:252:102:49)  11.697 ms * *
 4  * * 2a01:cfc4:0:1b00::13 (2a01:cfc4:0:1b00::13)  11.253 ms
 5  acorus.th2-1.hopus.net (2a02:e5c:1:35::2)  11.554 ms  11.580 ms  11.633 ms
 6  2a05:f440:8000::a5 (2a05:f440:8000::a5)  11.769 ms  11.202 ms  11.193 ms
 7  2a05:f440:0:1::12 (2a05:f440:0:1::12)  11.265 ms  11.638 ms  11.496 ms
 8  2a05:f440:0:1::8 (2a05:f440:0:1::8)  12.326 ms  12.271 ms  12.223 ms
 9  2a0e:9900:: (2a0e:9900::)  11.479 ms  11.526 ms  11.576 ms
10  2a07:a8c0:: (2a07:a8c0::)  11.924 ms  12.242 ms  12.152 ms

Thanks.