Paul de Weerd <[EMAIL PROTECTED]> wrote:
> | Link-local v6 addresses also work fine because they don't involve
> | neighbor discovery.
>
> Uhm, why ?
>
> 23:37:41.664994 00:0c:29:e5:f9:24 33:33:ff:ff:4d:0d 86dd 86:
> fe80::20c:29ff:fee5:f924 > ff02::1:ffff:4d0d: icmp6: neighbor sol: who
> has fe80::20c:29ff:feff:4d0d(src lladdr: 00:0c:29:e5:f9:24) (len 32,
> hlim 255)
I stand corrected.
> How would you determine the linklayer address of your neighbour without
> neighbor discovery ?
Well, you could, since the link-local address is reversibly constructed
from the link-layer address. On further reflection, I realize that
not all the world is ethernet and this relation might not be true
for other types of interfaces.
Vexingly, I seem to remember that at one time I actually verified
this behavior. I must have made a mistake then.
My interest was the influence of neighbor discovery on NTP. Some
fresh tcpdumping here shows that the typical packet exchange goes
like this:
0 sec NTP request --->
<----- NTP reply
+5 sec neighbor sol -->
<-- neighbor adv
<-- neighbor sol
neighbor adv -->
That seems counterintuitive, but it is nice for NTP.
--
Christian "naddy" Weisgerber [EMAIL PROTECTED]
