[LUNI] Fake Link Connection?

[Seva Epsteyn]

If this is what I think he is talking about, the situation is the following.

There is a physical switch that cuts the connection between the PC in
the "lock up" and the network connection to the rest of the world.
When certain time comes the PC as allowed to communicate with the rest
of the world by someone flipping the physical switch.

There are actually a few competing companies trying to get the same
financial news information from the "lock up" to the outside in the
automated trading world as fast as possible after the switch is
flipped, so the milliseconds count.

I was passively involved in some of the discussions regarding this,
and the partial solution to this was to insert a hub on each side of
the physical cut-off switch to keep the link state as up, there are
all sorts of other issues related to this that are unrelated to Linux
itself and are not being mentioned.

Seva

On Thu, Jul 30, 2009 at 18:01, Martin Maney<maney at two14.net> wrote:
> On Thu, Jul 30, 2009 at 11:41:19AM -0500, Samir Faci wrote:
>> laptop ------physical link     --------SS -------- switch --------cloud
>>
>> so basically the SS (special switch, named by yours truly for lack of a
>> better name) is just an on off switch that's enabled at a particular time
>> that allows the laptop to broadcast.  The time it takes for the laptop to
>> realize it has a link before it can send is too long, (1-2 seconds), what
>> we're trying to do is make the network card think it's always connected, so
>> it'll skip the check for link, and just send data as soon as the SS is
>> flipped.
>
> Sounds like pissing into the wind.  Why don't you just have a cron job
> ifup/ifdown the interface?
>
> And, okay, I can't resist: what sort of crackbrained solution to what
> is this?  :-)
>
> --
> automation: replacing what works with something that almost works,
> but which is faster and cheaper.  - attributed to Roger Needham
>
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