Looking at section 7.2.5 in RFC,

7.2.5. Receipt of Neighbor Advertisements
When a valid Neighbor Advertisement is received (either solicited or
unsolicited), the Neighbor Cache is searched for the target’s entry.
If no entry exists, the advertisement SHOULD be silently discarded.
There is no need to create an entry if none exists, since the
recipient has apparently not initiated any communication with the
target.

That explains in part the behavior being observed.


Regards
Vineet

On Wed, Aug 18, 2010 at 12:24 AM, A Gagne <community-noreply@qnx.com> wrote:

> I am trying to force an entry to be added to the neighbor table.
>
> An entry can be added manually using
> ndp -s (desired address) (mac address)
>
> If this is done, entries for (desired address) are created in the ndp and
> routing tables, which can be inspected and verified with ndp -a and route
> show. When these entries exist, communication with the device (desired
> address) work.
>
> I am generating an unsolicited neighbor advertisement in an attempt to
> automatically create the entries in the tables and duplicate the behavior
> that occurs when the ndp -s command is performed manually. I want it to
> occur automatically when the device with (desired address) is available.
>
> Since it is known when it is available, and its ipv6 and mac address are
> known, I filled in an unsolicited neighbor advertisement packet and sent it
> on its behalf to iopkt.
>
> When this is done,an entry gets created for (desired address) in the
> neighbor table, but the MAC address is missing. It shows (incomplete)
> instead. Could this mean the packet that was created was not formed
> correctly? I did verify the override flag is set. Can this be achieved with
> an unsolicited neighbor advertisement message or can this only be achieved
> by responding to a neighbor solicitation request?
>
>
>
>
> _______________________________________________
>
> General
> http://community.qnx.com/sf/go/post63300
>
>