From owner-freebsd-stable Mon Jun 19 4:13:49 2000 Delivered-To: freebsd-stable@freebsd.org Received: from mailhub.unibe.ch (mailhub.unibe.ch [130.92.254.109]) by hub.freebsd.org (Postfix) with ESMTP id C666D37BCBA for ; Mon, 19 Jun 2000 04:13:45 -0700 (PDT) (envelope-from roth@iamexwi.unibe.ch) Received: from CONVERSION-DAEMON by mailhub.unibe.ch (PMDF V5.2-32 #42480) id <0FWE00701F1FGJ@mailhub.unibe.ch> for freebsd-stable@FreeBSD.ORG; Mon, 19 Jun 2000 13:10:38 +0200 (MET DST) Received: from iamexwi.unibe.ch (haegar.unibe.ch [130.92.71.10]) by mailhub.unibe.ch (PMDF V5.2-32 #42480) with ESMTP id <0FWE001JVF1EP8@mailhub.unibe.ch>; Mon, 19 Jun 2000 13:10:27 +0200 (MET DST) Received: from degas.unibe.ch (degas [130.92.62.31]) by iamexwi.unibe.ch (8.8.8+Sun/8.8.8) with ESMTP id NAA05684; Mon, 19 Jun 2000 13:13:51 +0200 (MET DST) Received: from localhost (roth@localhost) by degas.unibe.ch (8.9.1b+Sun/8.9.1) with ESMTP id NAA17999; Mon, 19 Jun 2000 13:13:45 +0200 (MET DST) Date: Mon, 19 Jun 2000 13:13:45 +0200 (MET DST) From: Tobias Roth Subject: Re: hosts.allow: deny set but ping requests come through In-reply-to: <0v66r6gcej.fsf@cs.uni-magdeburg.de> X-Sender: roth@degas To: Roland Jesse Cc: freebsd-stable@FreeBSD.ORG Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Content-transfer-encoding: 7BIT X-Authentication-warning: degas.unibe.ch: roth owned process doing -bs Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > The first two lines of my /etc/hosts.allow are as follows: > > ALL : PARANOID : RFC931 20 : deny > ALL : general.URZ.Uni-Magdeburg.DE 141.44.2.1 : deny > > The second one is there to prevent ping requests from the specified > machine to mine without a need to set up a firewall. > > Using "tcpdump -a -i tx0 host arthur.cs.uni-magdeburg.de | grep general" > I still get the following: > > tcpdump: listening on tx0 > 12:53:38.083288 general.URZ.Uni-Magdeburg.DE > arthur.CS.Uni-Magdeburg.De: icmp: echo request > 12:53:38.083316 arthur.CS.Uni-Magdeburg.De > general.URZ.Uni-Magdeburg.DE: icmp: echo reply The 2nd line from hosts.allow says: # hosts.allow access control file for "tcp wrapped" applications. From that line you can get the following information: Access control works only with tcp wrapped applications. Your tcp dump says that you send out an ICMP reply. ICMP != tcp. greets, Tobe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message