Date: Wed, 21 Jan 2004 10:11:21 +0100 From: Jonas Bulow <xfree@bulow.mine.nu> To: freebsd-net@freebsd.org Subject: netgraph: ng_eiface and bpf gives duplicate packets Message-ID: <400E4239.7080708@bulow.mine.nu>
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Hi, Using bpf with ng_eiface results in duplication of all incoming packets. The duplicated packet is only "visible" on the bpf tap and the ngeth interface works as expected besides this behaviour with bpf. The following examplifies the problem: (pasted from my memory) ngctl -f- <<EOF mkpeer eiface dummy ether name .:dummy eif0 rmhook .:dummy msg eif0: setpromisc 1 msg eif0: setautosrc 0 connect fxp0: eif0: lower ether EOF ifconfig ngeth0 link c0:00:00:00:80:00 ifconfig ngeth0 up tcpdump-n -i ngeth0 <send one icmp echo to fxp0> tcpdump: WARNING: ngeth0: no IPv4 address assigned tcpdump: listening on ngeth0 09:53:38.200941 192.168.2.6 > 192.36.125.18: icmp: echo request 09:53:38.200949 192.168.2.6 > 192.36.125.18: icmp: echo request ^C 2 packets received by filter 0 packets dropped by kernel "netstat -i -I ngeth0" shows only one incoming packet. If I attach a ng_tee between the fxp's lower and upper hook (ng_ether) and then attache the eif0 ether hook to correct tap on the tee, I see the smae behaviour but can also se that a tcpdump on fxp0 show only one packet. Any hints on what's wrong? This problem occurs on a late FreeBSD 4.9-STABLE. /jonas
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