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



Lars Schotte <gustik%gustik.eu@localhost> writes:

> 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.

> On Linux I saw that Linux gets around this problem with having all
> zeroes as the MACADDR of the loopback device. FreeBSD does not show any
> loopback devices with ndp -a so neighbor discovery seems to be disabled
> for loopback on FreeBSD by default also for the device itself.

It looks like lo0 has no MAC address, which makes sense.   It may or may
not be a bug that there is an NDP entry.

> When i call ndp -a on NetBSD i get the following (among others):
> fe80::1%lo0   (incomplete)    lo0 permanent R
> cool, but on Linux I have only ::1 as the lo addrv6. So why is there
> any fe80::1%lo0 "link scan" address at all?

That's a 'link local' address.  I think every interface is required to
have one, and there's no reason they have anything to do with MAC
addresses.

I've been running IPv6 for many years with NetBSD, and it generally
works.  So you should perhaps post exactly what you are doing, what you
expect to see, and what you are seeing.   I would suggest posting to
netbsd-users, unless your mail e.g. contains an analysis from the
standards and is pointing out a particular proble.

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