From owner-freebsd-security Tue May 29 13:43: 8 2001 Delivered-To: freebsd-security@freebsd.org Received: from alpha.netvision.net.il (alpha.netvision.net.il [194.90.1.13]) by hub.freebsd.org (Postfix) with ESMTP id 5E3E637B422 for ; Tue, 29 May 2001 13:43:02 -0700 (PDT) (envelope-from lirandb@netvision.net.il) Received: from a ([213.57.143.184]) by alpha.netvision.net.il (8.9.3/8.8.6) with SMTP id XAA30887 for ; Tue, 29 May 2001 23:43:01 +0300 (IDT) Message-ID: <010f01c0e888$5ab3c120$b88f39d5@a> From: "Liran Dahan" To: Subject: Syn+Fin (Setup) And TCP RST Date: Tue, 29 May 2001 23:43:09 +0200 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_010C_01C0E899.1E135E40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org This is a multi-part message in MIME format. ------=_NextPart_000_010C_01C0E899.1E135E40 Content-Type: text/plain; charset="windows-1255" Content-Transfer-Encoding: quoted-printable I've added those 2 options in my kernel long time ago: options TCP_DROP_SYNFIN #drop TCP packets with SYN+FIN options TCP_RESTRICT_RST #restrict emission of TCP RST = =20 Is this could be the reason why even when i add in my firewall to send = RST packets, it takes me 30 seconds till i get timeout of Connection = refused when i telneting my box on randomly closed ports.. ?=20 And about TCP_DROP_SYNFIN .. is this could be one of the reasons 'setup' = command 'aint working on my ipfw? If my speculations are true... Why those kernel options are used for? Thanks, Liran Dahan (lirandb@netvision.net.il) ------=_NextPart_000_010C_01C0E899.1E135E40 Content-Type: text/html; charset="windows-1255" Content-Transfer-Encoding: quoted-printable

I've added those 2 options in my kernel = long time=20 ago:

options =20 TCP_DROP_SYNFIN #drop = TCP=20 packets with = SYN+FIN
options =20 TCP_RESTRICT_RST #restrict = emission of=20 TCP RST =

Is this could be the reason why even = when i add in=20 my firewall to send RST packets, it takes me 30 seconds till i get = timeout of=20 Connection refused when i telneting my box on randomly closed ports.. ?=20

And about TCP_DROP_SYNFIN .. is this = could be one=20 of the reasons 'setup' command 'aint working on my ipfw?

If my speculations are true... Why = those kernel=20 options are used for?

Thanks,

Liran = Dahan (lirandb@netvision.net.il)

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