On 25/07/2017 09:10, Tore Anderson wrote: > * Brian E Carpenter > >> So, I'm not aware of any realistic case where this happens, or any >> reason for it. > > As Gert already pointed out: Neighbour Discovery.
Well yes, like ARP. But that's the exception that proves the rule - you do it when that is really what you mean *and* the target address is within an on-link prefix. I can do it too, even from Windows: ping -n 100 -S fe80::c0de:dead:beef:768e%11 2001:df0:0:2006:c0de:beef:dead:be83 Those addresses are obfuscated, but you get the idea, and I see the ICMPv6 packets with Wireshark, but get no replies. Why would you ever do it for normal traffic? And why would ACLs be relevant for on-link traffic? Brian > > A few examples from an IX near me: > > 23:06:11.020045 In IP6 fe80::8678:acff:fe66:80db > 2001:7f8:12:1::3:9029: > ICMP6, neighbor solicitation, who has 2001:7f8:12:1::3:9029, length 32 > 23:06:11.563763 In IP6 fe80::aa0c:dff:fe71:5768 > 2001:7f8:12:1::3:9029: > ICMP6, neighbor solicitation, who has 2001:7f8:12:1::3:9029, length 32 > 23:06:29.958824 In IP6 fe80::92e2:baff:fe3f:7665 > 2001:7f8:12:1::3:9029: > ICMP6, neighbor solicitation, who has 2001:7f8:12:1::3:9029, length 32 > 23:06:34.239488 In IP6 fe80::523d:e5ff:fe89:4ec4 > 2001:7f8:12:1::3:9029: > ICMP6, neighbor solicitation, who has 2001:7f8:12:1::3:9029, length 32 > 23:06:45.177659 In IP6 fe80::2c1:64ff:fe60:380 > 2001:7f8:12:1::3:9029: > ICMP6, neighbor solicitation, who has 2001:7f8:12:1::3:9029, length 32 > > Tore > . >
