From owner-freebsd-net Mon Apr 16 13: 8:22 2001 Delivered-To: freebsd-net@freebsd.org Received: from obsecurity.dyndns.org (adsl-63-207-60-27.dsl.lsan03.pacbell.net [63.207.60.27]) by hub.freebsd.org (Postfix) with ESMTP id 6F73837B422; Mon, 16 Apr 2001 13:08:15 -0700 (PDT) (envelope-from kris@obsecurity.org) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 0CFD5678B8; Mon, 16 Apr 2001 13:08:15 -0700 (PDT) Date: Mon, 16 Apr 2001 13:08:14 -0700 From: Kris Kennaway To: Darren Reed Cc: Kris Kennaway , Mike Silbersack , Mark T Roberts , freebsd-security@FreeBSD.ORG, net@FreeBSD.ORG Subject: Re: non-random IP IDs Message-ID: <20010416130814.A12057@xor.obsecurity.org> References: <20010416120630.C10023@xor.obsecurity.org> <200104162002.GAA09062@caligula.anu.edu.au> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="M9NhX3UHpAaciwkO" Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200104162002.GAA09062@caligula.anu.edu.au>; from avalon@coombs.anu.edu.au on Tue, Apr 17, 2001 at 06:02:42AM +1000 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org --M9NhX3UHpAaciwkO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 17, 2001 at 06:02:42AM +1000, Darren Reed wrote: > > > You should optimize it for mod being 2^n-1 (or make that a requiremen= t). > >=20 > > I'm afraid I don't have time to look at this right now. Perhaps it > > can be revisited (the sysctl defaults to off for now), or Niels Provos > > may be interested in the idea. >=20 > Basically it means '% mod' -> '& mod' and call it with a 2^n-1 number. Oh, okay. > > Well, it still has wrapping properties like a network-order counter, > > i.e. the algorithm attempts to order the output so that it doesn't > > wrap within the segment lifetime. That would be lost without using > > HTONS. >=20 > You're confusing properties of the local number and some opaque bits in > a packet being sent over the 'net. Quite likely. Kris --M9NhX3UHpAaciwkO Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iD8DBQE621EuWry0BWjoQKURApyyAKCBB7Zt5a4iTdLd/p5UfsjwffMpBwCfScng oR2Ef5UAJZl7DV94q312HM0= =hVp+ -----END PGP SIGNATURE----- --M9NhX3UHpAaciwkO-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message