From owner-freebsd-bugs@FreeBSD.ORG Thu May 22 14:10:05 2008 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6A361106566C for ; Thu, 22 May 2008 14:10:05 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 4AC868FC25 for ; Thu, 22 May 2008 14:10:05 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m4MEA4SZ093380 for ; Thu, 22 May 2008 14:10:04 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m4MEA4lI093377; Thu, 22 May 2008 14:10:04 GMT (envelope-from gnats) Date: Thu, 22 May 2008 14:10:04 GMT Message-Id: <200805221410.m4MEA4lI093377@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Maxim Konovalov Cc: Subject: Re: kern/123881: Turning on TCP blackholing causes slow localhost connections X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Maxim Konovalov List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 May 2008 14:10:05 -0000 The following reply was made to PR kern/123881; it has been noted by GNATS. From: Maxim Konovalov To: Tom Karpik Cc: bug-followup@freebsd.org Subject: Re: kern/123881: Turning on TCP blackholing causes slow localhost connections Date: Thu, 22 May 2008 17:40:35 +0400 (MSD) > Turning on TCP blackholing (sysctl net.inet.tcp.blackhole=2) seems > to make connecting to some local services very slow. > > Example: telnet localhost 25 (default local Sendmail daemon after > fresh installation of FreeBSD) > > Sendmail responds with its greeting string right away if blackholing > is off. If it's turned on, it takes about 8-12 seconds for the > greeting to show up. Just an idea -- sendmail tries to use ident service and just timeouts on it due to tcp blackholing. To check this idea try to run e.g. inetd(8) auth service. -- Maxim Konovalov