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Re: ndp -a stops for a while because of lo0

>> I noticed that on NetBSD 6.0, when you want ndp to show you the
>> entries table it stops first for a while because he looks also on
>> lo0 so on the loopback device which does not have any linklayer
>> address on NetBSD.

> use '-n' to disable dns.  on my machine, 'ndp -a' is quick.

It is on mine too, even without -n.  But mine are 4.0.1 and 5.1; I
don't know whether this is because of something about name resolution
on my network or because it's not 6.x, but it's another data point.
Snooping port-53 traffic seems to imply ndp is not even trying to
resolve the link-local addresses to names - I see PTR queries for the
globally routed addresses but none for the link-local addresses (on any
interface, lo0 or not).

>> On Linux I saw that Linux gets around this problem with having all
>> zeroes as the MACADDR of the loopback device.  [...]
> It looks like lo0 has no MAC address, which makes sense.

I agree.  lo0 is not even vaguely Ethernettish, so there's no reason
for it to have a MAC, any more than I'd expect ppp0 to have a MAC.

>> When i call ndp -a on NetBSD i get the following (among others):
>> fe80::1%lo0  (incomplete)    lo0 permanent R

I see the same (modulo whitespace).

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