[CentOS-mirror] How mirror selection works

[Anssi Johansson]

Sebastian Sala kirjoitti:
> Hello again
> 
> I've noticed that the issue with strange mirror selection applies only 
> with IPv6 addressing  (I deployed it in the same period of time when the 
> systems started to use USA mirrors as the fastest one). When I disable 
> IPv6 on the host it starts to use my mirror.

Yes, the reason why your mirror 
http://mirror-pl.kielcetechnologypark.net/centos/ is not listed on the 
IPv6 mirror list is that all the IPv6 mirror monitoring nodes (in ASs 
31211, 29169, 13213, 6939) have problems connecting to your mirror.

I don't know what's going on, but..

$ ping6 mirror-pl.kielcetechnologypark.net
PING mirror-pl.kielcetechnologypark.net(2001:67c:1b8c:1100:603::5) 56 
data bytes
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=1 ttl=55 time=52.5 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=2 ttl=55 time=58.3 ms
 From 2a02:f40:d100:2::2 icmp_seq=3 Destination unreachable: Unknown code 6
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=4 ttl=55 time=52.1 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=5 ttl=55 time=52.2 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=6 ttl=55 time=53.5 ms
 From 2a02:f40:d100:2::2 icmp_seq=7 Destination unreachable: Unknown code 6
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=8 ttl=55 time=52.3 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=9 ttl=55 time=52.2 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=10 ttl=55 time=52.5 ms
 From 2a02:f40:d100:2::2 icmp_seq=11 Destination unreachable: Unknown code 6
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=12 ttl=55 time=52.1 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=13 ttl=55 time=52.2 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=14 ttl=55 time=52.2 ms
 From 2a02:f40:d100:2::2 icmp_seq=15 Destination unreachable: Unknown code 6
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=16 ttl=55 time=52.2 ms
64 bytes from 2001:67c:1b8c:1100:603::5: icmp_seq=17 ttl=55 time=55.8 ms

$ telnet mirror-pl.kielcetechnologypark.net 80
Trying 2001:67c:1b8c:1100:603::5...
Connected to mirror-pl.kielcetechnologypark.net.
Escape character is '^]'.
Connection closed by foreign host.
(connection closed immediately)

$ telnet mirror-pl.kielcetechnologypark.net 80
Trying 2001:67c:1b8c:1100:603::5...
telnet: connect to address 2001:67c:1b8c:1100:603::5: Protocol error

Perhaps you should try connecting to your mirror from outside of your 
network over IPv6. Once you've figured out the problem and fixed it, the 
CentOS IPv6 mirrorlist servers will start directing traffic to your 
server again.