From owner-freebsd-net Tue Jun 4 20: 0:32 2002 Delivered-To: freebsd-net@freebsd.org Received: from wren.cs.unc.edu (wren.cs.unc.edu [152.2.128.86]) by hub.freebsd.org (Postfix) with ESMTP id 368C137B400 for ; Tue, 4 Jun 2002 20:00:24 -0700 (PDT) Received: from capefear.cs.unc.edu (capefear.cs.unc.edu [152.2.128.19]) by wren.cs.unc.edu (8.9.3/8.9.3) with ESMTP id XAA20101; Tue, 4 Jun 2002 23:00:22 -0400 (EDT) Date: Tue, 4 Jun 2002 23:00:22 -0400 (EDT) From: Nguyen-Tuong Long Le To: freebsd-net@FreeBSD.ORG Cc: Nguyen-Tuong Long Le Subject: Re: Problem with SYN cache in FreeBSD 4.5 In-Reply-To: <20020604194538.J42854-100000@patrocles.silby.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hi, On Tue, 4 Jun 2002, Mike Silbersack wrote: > > On Tue, 4 Jun 2002, jayanth wrote: > > > Can you dump the output of netstat -s -p tcp ? > > Checking for listen queue overflows and syncache bucket overflows. > > > > jayanth > Here is the output of "netstat -s -p tcp". tcp: 264136 packets sent 104124 data packets (127937368 bytes) 286 data packets (344573 bytes) retransmitted 0 resends initiated by MTU discovery 147203 ack-only packets (127 delayed) 0 URG only packets 2 window probe packets 3 window update packets 12518 control packets 747675 packets received 85799 acks (for 127931017 bytes) 3247 duplicate acks 0 acks for unsent data 83750 packets (11689418 bytes) received in-sequence 89 completely duplicate packets (5552 bytes) 0 old duplicate packets 0 packets with some dup. data (0 bytes duped) 2 out-of-order packets (796 bytes) 0 packets (0 bytes) of data after window 0 window probes 30312 window update packets 0 packets received after close 0 discarded for bad checksums 0 discarded for bad header offset fields 0 discarded because packet too short 14 connection requests 17243 connection accepts 372055 bad connection attempts 87501 listen queue overflows 17257 connections established (including accepts) 16695 connections closed (including 1 drop) 830 connections updated cached RTT on close 830 connections updated cached RTT variance on close 178 connections updated cached ssthresh on close 0 embryonic connections dropped 85798 segments updated rtt (of 50455 attempts) 201 retransmit timeouts 0 connections dropped by rexmit timeout 0 persist timeouts 0 connections dropped by persist timeout 0 keepalive timeouts 0 keepalive probes sent 0 connections dropped by keepalive 376 correct ACK header predictions 61279 correct data packet header predictions 104747 syncache entries added 189 retransmitted 285 dupsyn 0 dropped 17243 completed 0 bucket overflow 0 cache overflow 3 reset 0 stale 87501 aborted 0 badack 0 unreach 0 zone failures 0 cookies sent 0 cookies received > And "netstat -La" too, please. I'm interested in if you're accepting > sockets fast enough. Here is the output of "netstat -La" Current listen queue sizes (qlen/incqlen/maxqlen) Proto Listen Local Address tcp4 3/0/8192 *.6789 I wonder why the listen queue overflows when there are so few connections in the queue. The number of listen queue overflows is equal to the number of syncache aborts. Is it a coincidence or are they related? Thanks, -- long To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message