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On Wed, Mar 17, 2004 at 09:48:44PM -0800, Sumit chauhan wrote:

> I am new to netbsd and looking for some info on netbsd behaviour for=20
> syn flooding.
> > From what I learn there were many ways proposed to handle this like=20
> > syn proxy, etc.
> Syn cache and rst cookies being most popular.
>=20
> I can see that tcp_input.c does has some code for handling of these.
> but I am new and so was wondering if some one can update me on the=20
> known behaviour of netbsd 1.6.1  under syn attack ? are connections for=
=20
> new clients accepted with ease ?

"syn cookies" is a strategy to avoid to keep a full connection control
block for a partial connection.

The NetBSD strategy is different, but also designed to withstand a huge
amount of partial connections without using much resources (e.g., memory).

search the tech-net or tech-kern mailing list for "syn flood attack";
you should be able to find a discussion on how the code is supposed to
work and what kind of load it can survive. For the details, you'll have
to read the source code...

Regards,
	-is

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