Re: [lwip-devel] Call nd6_reachability_hint for received packets

[Ivan Delamer]

Hi Philipp,

The reason why reachability hints are implemented only in TCP is that in
order to mark a neighbour as REACHABLE we must have information of
bidirectional reachability. Receiving a packet tells us of reachability in
one direction, but does not guarantee reachability in the opposite
direction. The TCP ACK mechanism guarantees this. Of course, also does the
neighbor reachability detection part of ND.

Cheers
Ivan


> Date: Thu, 27 Sep 2012 16:02:19 +0200
> From: Philipp T?lke <address@hidden>
> To: lwip-devel <address@hidden>
> Subject: [lwip-devel] Call nd6_reachability_hint for received packets
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-15
>
> Hi everyone,
>
> I am sure that I read a discussion about this topic on some lwip-* list
> already but can't find it in the archives.
>
> Would it be viable to mark an nd6 neighbour cache entry as "reachable"
> when receiving a packet from this neighbour (both IP address and MAC
> address have to match) and not only when it ACKs a TCP-segment?
>
> Regards,
> --
> Philipp T?lke, M.Sc. - Software-Developer - fos4X GmbH - www.fos4x.de
> Thalkirchner Str. 210, Geb. 6 - D-81371 M?nchen; AG M?nchen HRB 189 218
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