[OLPC Networking] TCP is broken in mesh mode

[Chris Ball]

Hi,

   > If an invitation works once between two laptops, it continues to
   > work between them reliably.  If it fails once, it continues to fail
   > between them consistently.

I think I've seen an analog of this problem but with activity joining
rather than invitations.  http://dev.laptop.org/ticket/6739 -- as the
comments show, these machines were able to ping each other throughout
the test, but were not receiving each other's multicast packets.
Tcpdump didn't show the clique packets coming in even though each host's
tcpdump log thought it was sending them to the other.  As Sjoerd said:

   Ping is unicast traffic. While Clique uses multicast.. So apparently
   for some reason multicast isn't getting through. Your logs only had
   the tcpdump for the joining side, but i'm pretty sure the sharing
   side would show a similar picture.. Which would mean it's a
   kernel/firmware issue.

- Chris.
-- 
Chris Ball   <cjb at laptop.org>