Hi Horio, Cheers for reply.
On Fri, Dec 05, 2003 at 07:33:49PM +0900, horio shoichi wrote: > On Fri, 5 Dec 2003 00:24:12 +0000 > Jez Hancock <[EMAIL PROTECTED]> wrote: > > Hi, > > > > I've blocked a dozen or so addresses using ipfilter: > > > > block in quick on fxp0 from 184.108.40.206 to any > > block in quick on fxp0 from 220.127.116.11 to any > > > > etc > > > > but I still see a lot of traffic those hosts in trafshow, snort and > > other packet capturing utils. Why is this? > > You are probably seeing the supposedly blocked packets on the "outside" of > network. Observe them on "inside", i.e., on the interface not fxp0. Not sure what you mean here, what command would you issue via tcpdump or snort to do what you suggest? > What you are seeing are packets ipfilter is just about to handle. Right - it's just I would have thought that ipfilter handled packets before they reached any traffic dumping utils. I see what you're getting at. Presumably snort for example uses the bpf driver via pcap(?) to capture network traffic... actually reading bpf(4) clears things up a little: Associated with each open instance of a bpf file is a user-settable packet filter. Whenever a packet is received by an interface, all file descriptors listening on that interface apply their filter. Each descriptor that accepts the packet receives its own copy. > > Is there any alternative method of blocking access from certain hosts > > so that this traffic is not 'seen' by higher level /userland apps? > I don't understand your second question. Are you thinking about tcp wrapper, > reset feature of snort, etc ? Let me rephrase that one :P I meant is there a method - for example such as adding some kind of routing via arp - so that packets are dropped on the floor even quicker than they would be via the firewall method? -- Jez Hancock - System Administrator / PHP Developer http://munk.nu/ _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"