gandalf2016 questa cosa l'ho notata anch'io e una situazione simile mi pare la abbia anche @Alfoele
Altra cosa strana che ho notato ad esempio con google, se provo a raggiungere google Milano va in timeout, verso Amsterdam funziona
root@dckh:~# ping6 -c4 mil07s12-in-x0e.1e100.net
PING mil07s12-in-x0e.1e100.net(mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e)) 56 data bytes
--- mil07s12-in-x0e.1e100.net ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3055ms
root@dckh:~# ping6 -c4 ams17s08-in-x0e.1e100.net
PING ams17s08-in-x0e.1e100.net(ams17s08-in-x0e.1e100.net (2a00:1450:400e:80e::200e)) 56 data bytes
64 bytes from ams17s08-in-x0e.1e100.net (2a00:1450:400e:80e::200e): icmp_seq=1 ttl=114 time=25.2 ms
64 bytes from ams17s08-in-x0e.1e100.net (2a00:1450:400e:80e::200e): icmp_seq=2 ttl=114 time=21.7 ms
64 bytes from ams17s08-in-x0e.1e100.net (2a00:1450:400e:80e::200e): icmp_seq=3 ttl=114 time=21.4 ms
64 bytes from ams17s08-in-x0e.1e100.net (2a00:1450:400e:80e::200e): icmp_seq=4 ttl=114 time=21.1 ms
--- ams17s08-in-x0e.1e100.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 21.130/22.346/25.197/1.657 ms
L'host di Milano se lo provo da un altra connessione non Fastweb risponde:
root@mail2:~# ping6 -c4 mil07s12-in-x0e.1e100.net
PING mil07s12-in-x0e.1e100.net(mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e)) 56 data bytes
64 bytes from mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e): icmp_seq=1 ttl=57 time=13.5 ms
64 bytes from mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e): icmp_seq=2 ttl=57 time=12.7 ms
64 bytes from mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e): icmp_seq=3 ttl=57 time=12.7 ms
64 bytes from mil04s27-in-x0e.1e100.net (2a00:1450:4002:809::200e): icmp_seq=4 ttl=57 time=13.0 ms
--- mil07s12-in-x0e.1e100.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 7ms
rtt min/avg/max/mdev = 12.656/12.938/13.453/0.341 ms