From owner-freebsd-bugs@freebsd.org Tue Feb 16 09:51:56 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2CBB5AA9B18 for ; Tue, 16 Feb 2016 09:51:56 +0000 (UTC) (envelope-from maxim.konovalov@gmail.com) Received: from mp2.macomnet.net (mp2.macomnet.net [195.128.64.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B1D9711EE; Tue, 16 Feb 2016 09:51:55 +0000 (UTC) (envelope-from maxim.konovalov@gmail.com) Received: from localhost (localhost [127.0.0.1]) by mp2.macomnet.net (8.15.2/8.15.2) with ESMTP id u1G9pj1b004772; Tue, 16 Feb 2016 12:51:45 +0300 (MSK) (envelope-from maxim.konovalov@gmail.com) Date: Tue, 16 Feb 2016 12:51:45 +0300 (MSK) From: Maxim Konovalov To: bugzilla-noreply@freebsd.org cc: freebsd-bugs@FreeBSD.org Subject: Re: [Bug 207208] ping has a problem with fragmented replies In-Reply-To: Message-ID: References: User-Agent: Alpine 2.20 (BSF 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Feb 2016 09:51:56 -0000 Hello, > # netstat -sp ip > ip: > 0 fragments received {...] > 22 datagrams that can't be fragmented > [...] The above looks suspicious. Here is what it should be: # netstat -sz >/dev/null # netstat -sp ip | grep frag 0 fragments received 0 fragments dropped (dup or out of space) 0 fragments dropped after timeout 0 output datagrams fragmented 0 fragments created 0 datagrams that can't be fragmented # ping -qc 1 -s 2500 80.113.23.178 PING 80.113.23.178 (80.113.23.178): 2500 data bytes --- 80.113.23.178 ping statistics --- 1 packets transmitted, 1 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 59.983/59.983/59.983/0.000 ms # netstat -sp ip | grep frag 2 fragments received 0 fragments dropped (dup or out of space) 0 fragments dropped after timeout 1 output datagram fragmented 2 fragments created 0 datagrams that can't be fragmented To test ip fragmentation withoug NAT you can simple run ping -s 32000 -c1 127.0.0.1 and check stats above. I still think that your NAT is culprit. -- Maxim Konovalov