NetBSD Problem Report #35228

From  Sun Dec 10 22:42:36 2006
Return-Path: <>
Received: from ( [])
	by (Postfix) with ESMTP id 54A3A63BA6D
	for <>; Sun, 10 Dec 2006 22:42:36 +0000 (UTC)
Message-Id: <>
Date: Sun, 10 Dec 2006 16:07:13 -0500 (EST)
Subject: ath and tcpdump don't mix
X-Send-Pr-Version: 3.95

>Number:         35228
>Category:       kern
>Synopsis:       ath and tcpdump don't mix
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Dec 10 22:45:00 +0000 2006
>Originator:     Perry E. Metzger
>Release:        NetBSD 4.99.3
Perry E. Metzger
"Ask not what your country can force other people to do for you..."

System: NetBSD hackworth 4.99.3 NetBSD 4.99.3 (HACKWORTH) #0: Fri Oct 27 14:05:48 EDT 2006 perry@hackworth:/usr/obj/sys/arch/i386/compile/HACKWORTH i386
Architecture: i386
Machine: i386

If you do a tcpdump on an ath interface, it quits receiving packets
from the rest of the world, though it doesn't show any apparent
problems if you ifconfig the interface in another window. I suspect
this is a promiscuous mode problem rather than a bpf problem, but I
haven't looked into the details. The interface fails to get back to
normal until you down and up the interface again.


Try doing tcpdump on an ath device, say:

tcpdump -n -i ath0 host foo

Then watch as the tcpdump shows packets you send, but no others. Then
notice that all your connections are dead. Then kill the tcpdump --
you will need up and down the ath interface and wait some moments to
get connectivity again.



NetBSD Home
NetBSD PR Database Search

(Contact us) $NetBSD: query-full-pr,v 1.39 2013/11/01 18:47:49 spz Exp $
$NetBSD:,v 1.8 2006/05/07 09:23:38 tsutsui Exp $
Copyright © 1994-2007 The NetBSD Foundation, Inc. ALL RIGHTS RESERVED.