kern/123881: [tcp] Turning on TCP blackholing causes slow localhost connections

Oliver oliver at hotracer.de
Fri Aug 1 15:30:06 UTC 2008


The following reply was made to PR kern/123881; it has been noted by GNATS.

From: Oliver <oliver at hotracer.de>
To: bug-followup at FreeBSD.org, tom at tomkarpik.com
Cc:  
Subject: Re: kern/123881: [tcp] Turning on TCP blackholing causes slow localhost
 connections
Date: Fri, 01 Aug 2008 17:05:10 +0200

 I tried to reproduce this. You can log this issue when you also set
 net.inet.tcp.log_in_vain=2
 the dmesg output shows for each connection attempt to sendmail
 TCP: [127.0.0.1]:58148 to [127.0.0.1]:113 tcpflags 0x2<SYN>; tcp_input: 
 Connection attempt on closed port
 
 if you start inetd/auth (113) the sendmail deamon answers the same speed 
 it does with net.inet.tcp.blackhole=0
 
 If you don't want to use auth, sendmail can be configured to set the 
 timeout for ident to 0s which results in ident checking disabled or
 you can reduce the default value of 5 seconds.
 O Timeout.ident=0s
 
 so tcp.blackhole works as expected and perhaps this can be closed.
 
 Greetings, Oliver
 


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