From owner-freebsd-security Fri Oct 19 6:19:41 2001 Delivered-To: freebsd-security@freebsd.org Received: from blacklamb.mykitchentable.net (ekgr-dsl2-116.citlink.net [207.173.226.116]) by hub.freebsd.org (Postfix) with ESMTP id 1F18D37B401 for ; Fri, 19 Oct 2001 06:19:39 -0700 (PDT) Received: from bigdaddy (bigdaddy [192.168.1.3]) by blacklamb.mykitchentable.net (Postfix) with SMTP id E2E4BEE623 for ; Fri, 19 Oct 2001 06:00:04 -0700 (PDT) Message-ID: <003101c1589e$061ceac0$0301a8c0@bigdaddy> From: "Drew Tomlinson" To: Subject: OT: Data Packet Filters? Date: Fri, 19 Oct 2001 06:00:27 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 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 I'm hoping someone on this list will share his/her knowledge with me even though this is somewhat off-topic. :) I am trying to deny ICMP echo reply packets on my 3Com 812 ADSL modem/router. It appears that the only way to do this is to write a data filter. The fields I need to determine are offset (bytes - which I thought was 36 for ICMP code), length (bytes - I thought 1), Masked (hex - appears that FF is to match data exactly), and data (hex - I thought 0x0 echo reply). Can anyone get me pointed in the right direction? Any help or URLs will be most appreciated. Thanks! Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message