[pisa] Re: udp-problems with hip

  • From: Miika Komu <miika.komu@xxxxxxx>
  • To: pisa@xxxxxxxxxxxxx
  • Date: Sun, 21 Sep 2008 14:09:41 +0300

Wolfram Fischer wrote:

Hi,

Hi Miika,

I fixed some hip encapsulation on udp related problems which seems to be
also available on the latest midauth branch. However, I think you are
talking about missing ESP packets here with "conntest-client-hip udp".
That problem is related to IPsec, not hipd.
Linux IPsec does not implement queuing for IPsec, so the first UDP
packets might get dropped. The assumption in linux IPsec is that
transport layer protocols implement their own retransmission mechanisms.
This is not true with conntest-client-hip.. feel free to implement one
if you have time :)

This sounds very promising, I just wonder, why it sometimes works on the
first try and sometimes not!
Fortunately I think I only need to take care for the handshake - so I'll
give an implementation a try ^^.

the reason for "random" behavious might be a combination of timing (race problem) and the use of networking of virtual machines.

When the first udp packet gets lost, does a second conntest-client-hip udp attempt always succeed when the host association is still alive? If yes, it is the IPsec problem that I just described.

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