[Discuss] puzzle

[kentborg at borg.org (Kent Borg)]

On 4/28/23 11:20, dan moylan wrote:
> never used IPv6 -- don't know how.

Given:

    root at tinpan:~# ifconfig
    lo: flags=73<UP,LOOPBACK,RUNNING>? mtu 65536
     ??????? inet 127.0.0.1? netmask 255.0.0.0
     ??????? inet6 ::1? prefixlen 128? scopeid 0x10<host>
     ??????? loop? txqueuelen 1000? (Local Loopback)
     ??????? RX packets 4289? bytes 354712 (346.3 KiB)
     ??????? RX errors 0? dropped 0? overruns 0? frame 0
     ??????? TX packets 4289? bytes 354712 (346.3 KiB)
     ??????? TX errors 0? dropped 0 overruns 0? carrier 0? collisions 0

    wlp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>? mtu 1500
     ??????? inet 10.0.0.183? netmask 255.255.255.0? broadcast 10.0.0.255
     ??????? inet6 fe80::2880:cdbb:714:2a91? prefixlen 64? scopeid
    0x20<link>
     ??????? inet6 fd30:aa83:f3c6:0:3422:ecc1:2289:4038? prefixlen 64?
    scopeid 0x0<global>
     ??????? inet6 fd30:aa83:f3c6::d34? prefixlen 128? scopeid 0x0<global>
     ??????? inet6 fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a? prefixlen 64?
    scopeid 0x0<global>
     ??????? ether a8:7e:ea:59:91:6f? txqueuelen 1000? (Ethernet)
     ??????? RX packets 5106352? bytes 4487826142 (4.1 GiB)
     ??????? RX errors 0? dropped 10? overruns 0? frame 0
     ??????? TX packets 2681728? bytes 928272641 (885.2 MiB)
     ??????? TX errors 0? dropped 0 overruns 0? carrier 0? collisions 0

On a different machine:

    kentborg at la:~$ ping fd30:aa83:f3c6::d34
    PING fd30:aa83:f3c6::d34(fd30:aa83:f3c6::d34) 56 data bytes
    64 bytes from fd30:aa83:f3c6::d34: icmp_seq=1 ttl=64 time=48.1 ms
    64 bytes from fd30:aa83:f3c6::d34: icmp_seq=2 ttl=64 time=67.1 ms
    ^C
    --- fd30:aa83:f3c6::d34 ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 3ms
    rtt min/avg/max/mdev = 48.076/57.593/67.110/9.517 ms
    kentborg at la:~$ ^C
    kentborg at la:~$ ping fd30:aa83:f3c6:0:3422:ecc1:2289:4038
    PING
    fd30:aa83:f3c6:0:3422:ecc1:2289:4038(fd30:aa83:f3c6:0:3422:ecc1:2289:4038)
    56 data bytes
    64 bytes from fd30:aa83:f3c6:0:3422:ecc1:2289:4038: icmp_seq=1
    ttl=64 time=99.0 ms
    64 bytes from fd30:aa83:f3c6:0:3422:ecc1:2289:4038: icmp_seq=2
    ttl=64 time=19.6 ms
    ^C
    --- fd30:aa83:f3c6:0:3422:ecc1:2289:4038 ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 1ms
    rtt min/avg/max/mdev = 19.639/59.296/98.954/39.658 ms
    kentborg at la:~$ ^C
    kentborg at la:~$ ping fe80::2880:cdbb:714:2a91
    PING fe80::2880:cdbb:714:2a91(fe80::2880:cdbb:714:2a91) 56 data bytes
    64 bytes from fe80::2880:cdbb:714:2a91%enp3s0: icmp_seq=1 ttl=64
    time=2.27 ms
    64 bytes from fe80::2880:cdbb:714:2a91%enp3s0: icmp_seq=2 ttl=64
    time=14.9 ms
    ^C
    --- fe80::2880:cdbb:714:2a91 ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 3ms
    rtt min/avg/max/mdev = 2.274/8.607/14.941/6.334 ms
    kentborg at la:~$ ^C
    kentborg at la:~$ ping fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a
    PING
    fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a(fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a)
    56 data bytes
    64 bytes from fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a: icmp_seq=1
    ttl=64 time=2.94 ms
    64 bytes from fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a: icmp_seq=2
    ttl=64 time=86.3 ms
    ^C
    --- fd25:3cb2:b5fc:0:e075:f8a2:36b2:c08a ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 3ms
    rtt min/avg/max/mdev = 2.944/44.622/86.300/41.678 ms