Implementing aggressive link setup

[Guus Sliepen]

On Wed, Apr 21, 2010 at 11:26:57AM +0200, Michael Doering wrote:

> I would like to use tinc in a scenario with a mobile client passing a
> wireless accesspoint. A wireless link will be available for a time of
> only a few seconds. Therefore the encrypted connection should be setup
> as fast as possible. This means that both tinc-daemons should very
> aggressively try to connect to each other, e.g. 4 times a second. (I am
> aware that such a behavior wastes resources and is not desirable for
> normal operation.)
> 
> Is such an aggressive link-setup possible with tinc? Can it be
> configured? Or would I have to change the code? Is that feasible? Can
> you point out the parts of the code the would require modification?

You can try adding the following to tinc.conf on the mobile client:

MaxTimeout = 0
PingTimeout = 1

This will try to connect once a second. If you need it faster... either you
have to modify tinc to retry connecting every 250 ms, or modify the TCP
settings somehow so that it will retry sending SYN packets every 250 ms.

Another option, which would also require modification of tinc, is to keep the
session keys for UDP alive even if the TCP connection is down. This would then
not require an authentication phase when you pass that wireless access point
for only a few seconds.

-- 
Met vriendelijke groet / with kind regards,
     Guus Sliepen <guus at tinc-vpn.org>
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