From owner-freebsd-net@FreeBSD.ORG Sun May 22 20:17:50 2005 Return-Path: X-Original-To: freebsd-net@FreeBSD.org Delivered-To: freebsd-net@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 76FD416A41C for ; Sun, 22 May 2005 20:17:50 +0000 (GMT) (envelope-from tataz@tataz.chchile.org) Received: from postfix4-2.free.fr (postfix4-2.free.fr [213.228.0.176]) by mx1.FreeBSD.org (Postfix) with ESMTP id DAC9443D1F for ; Sun, 22 May 2005 20:17:49 +0000 (GMT) (envelope-from tataz@tataz.chchile.org) Received: from tatooine.tataz.chchile.org (vol75-8-82-233-239-98.fbx.proxad.net [82.233.239.98]) by postfix4-2.free.fr (Postfix) with ESMTP id BB19F31D8F1 for ; Sun, 22 May 2005 22:17:47 +0200 (CEST) Received: by tatooine.tataz.chchile.org (Postfix, from userid 1000) id 18F494080; Sun, 22 May 2005 22:17:49 +0200 (CEST) Date: Sun, 22 May 2005 22:17:49 +0200 From: Jeremie Le Hen To: freebsd-net@FreeBSD.org Message-ID: <20050522201748.GJ850@obiwan.tataz.chchile.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="7ZAtKRhVyVSsbBD2" Content-Disposition: inline User-Agent: Mutt/1.5.9i Cc: Subject: ICMP need to frag X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 May 2005 20:17:50 -0000 --7ZAtKRhVyVSsbBD2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline I try to connect to my RELENG_5 box through an IPsec tunnel whose MTU is 1260. CURRENT -------- [[ RELENG_5 ------- RELENG_4 ]] -------- RELENG_5 (client) Ethernet IPSec Ethernet (server) (1500) (1260) (1500) The attached tcpdump trace comes from the Ethernet side of the RELENG_4 router. I simply don't understand why the RELENG_5 ssh server doesn't take care of the ICMP need to frag packet. FYI, this trace is a screen reattachement through ssh which hangs during the screen refresh. After about ten seconds, I broke the ssh session with ~. . Advices are welcome :-). Thanks. Regards, -- Jeremie Le Hen < jeremie at le-hen dot org >< ttz at chchile dot org > --7ZAtKRhVyVSsbBD2 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=tcpdump 21:36:32.956062 192.168.4.205.49583 > 192.168.1.222.22222: S [tcp sum ok] 894016321:894016321(0) win 65535 (DF) (ttl 62, id 20835, len 64) 21:36:32.956359 192.168.1.222.22222 > 192.168.4.205.49583: S [tcp sum ok] 4232817296:4232817296(0) ack 894016322 win 65535 (DF) (ttl 64, id 40505, len 64) 21:36:33.022800 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 1 win 33304 (DF) (ttl 62, id 7512, len 52) 21:36:33.026219 192.168.1.222.22222 > 192.168.4.205.49583: P 1:42(41) ack 1 win 33304 (DF) (ttl 64, id 12375, len 93) 21:36:33.074338 192.168.4.205.49583 > 192.168.1.222.22222: P 1:40(39) ack 42 win 33304 (DF) (ttl 62, id 63234, len 91) 21:36:33.078374 192.168.1.222.22222 > 192.168.4.205.49583: P 42:642(600) ack 40 win 33304 (DF) (ttl 64, id 31837, len 652) 21:36:33.146521 192.168.4.205.49583 > 192.168.1.222.22222: P 40:672(632) ack 642 win 33004 (DF) (ttl 62, id 50720, len 684) 21:36:33.246659 192.168.1.222.22222 > 192.168.4.205.49583: . [tcp sum ok] ack 672 win 33304 (DF) (ttl 64, id 10111, len 52) 21:36:33.312116 192.168.4.205.49583 > 192.168.1.222.22222: P [tcp sum ok] 672:696(24) ack 642 win 33304 (DF) (ttl 62, id 49967, len 76) 21:36:33.317549 192.168.1.222.22222 > 192.168.4.205.49583: P 642:794(152) ack 696 win 33304 (DF) (ttl 64, id 37707, len 204) 21:36:33.403655 192.168.4.205.49583 > 192.168.1.222.22222: P 696:840(144) ack 794 win 33304 (DF) (ttl 62, id 8742, len 196) 21:36:33.414546 192.168.1.222.22222 > 192.168.4.205.49583: P 794:1450(656) ack 840 win 33304 (DF) (ttl 64, id 64355, len 708) 21:36:33.487303 192.168.4.205.49583 > 192.168.1.222.22222: P [tcp sum ok] 840:856(16) ack 1450 win 33304 (DF) (ttl 62, id 39201, len 68) 21:36:33.586646 192.168.1.222.22222 > 192.168.4.205.49583: . [tcp sum ok] ack 856 win 33304 (DF) (ttl 64, id 62491, len 52) 21:36:33.652541 192.168.4.205.49583 > 192.168.1.222.22222: P 856:904(48) ack 1450 win 33304 (DF) (ttl 62, id 34677, len 100) 21:36:33.652915 192.168.1.222.22222 > 192.168.4.205.49583: P 1450:1498(48) ack 904 win 33304 (DF) (ttl 64, id 53777, len 100) 21:36:33.714913 192.168.4.205.49583 > 192.168.1.222.22222: P 904:968(64) ack 1498 win 33304 (DF) (ttl 62, id 17208, len 116) 21:36:33.723843 192.168.1.222.22222 > 192.168.4.205.49583: P 1498:1562(64) ack 968 win 33304 (DF) (ttl 64, id 30315, len 116) 21:36:33.783353 192.168.4.205.49583 > 192.168.1.222.22222: P 968:1496(528) ack 1562 win 33304 (DF) (ttl 62, id 39754, len 580) 21:36:33.785714 192.168.1.222.22222 > 192.168.4.205.49583: P 1562:2042(480) ack 1496 win 33304 (DF) (ttl 64, id 82, len 532) 21:36:33.847665 192.168.4.205.49583 > 192.168.1.222.22222: P 1496:2072(576) ack 2042 win 33304 (DF) (ttl 62, id 16734, len 628) 21:36:33.866840 192.168.1.222.22222 > 192.168.4.205.49583: P 2042:2074(32) ack 2072 win 33304 (DF) (ttl 64, id 22114, len 84) 21:36:33.953365 192.168.4.205.49583 > 192.168.1.222.22222: P 2072:2136(64) ack 2074 win 33304 (DF) (ttl 62, id 63747, len 116) 21:36:33.954155 192.168.1.222.22222 > 192.168.4.205.49583: P 2074:2122(48) ack 2136 win 33304 (DF) (ttl 64, id 59449, len 100) 21:36:34.029129 192.168.4.205.49583 > 192.168.1.222.22222: P 2136:2536(400) ack 2122 win 33304 (DF) [tos 0x10] (ttl 62, id 14861, len 452) 21:36:34.033871 192.168.1.222.22222 > 192.168.4.205.49583: P 2122:2170(48) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 33133, len 100) 21:36:34.076084 192.168.1.222.22222 > 192.168.4.205.49583: P 2170:2218(48) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 9735, len 100) 21:36:34.082093 192.168.1.222.22222 > 192.168.4.205.49583: P 2218:2778(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 3421, len 612) 21:36:34.082277 192.168.1.222.22222 > 192.168.4.205.49583: P 2778:3338(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 1283, len 612) 21:36:34.082498 192.168.1.222.22222 > 192.168.4.205.49583: P 3338:3898(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 44070, len 612) 21:36:34.082558 192.168.1.222.22222 > 192.168.4.205.49583: P 3898:4458(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 31093, len 612) 21:36:34.082644 192.168.1.222.22222 > 192.168.4.205.49583: P 4458:4762(304) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 21000, len 356) 21:36:34.082849 192.168.1.222.22222 > 192.168.4.205.49583: P 4762:5322(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 26489, len 612) 21:36:34.083013 192.168.1.222.22222 > 192.168.4.205.49583: P 5322:5882(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 42545, len 612) 21:36:34.083206 192.168.1.222.22222 > 192.168.4.205.49583: P 5882:6186(304) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 35121, len 356) 21:36:34.084132 192.168.1.222.22222 > 192.168.4.205.49583: P 6186:6746(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 10853, len 612) 21:36:34.084301 192.168.1.222.22222 > 192.168.4.205.49583: P 6746:7306(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 15741, len 612) 21:36:34.084442 192.168.1.222.22222 > 192.168.4.205.49583: P 7306:7866(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 11118, len 612) 21:36:34.084530 192.168.1.222.22222 > 192.168.4.205.49583: P 7866:8170(304) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 8710, len 356) 21:36:34.085301 192.168.1.222.22222 > 192.168.4.205.49583: P 8170:8730(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 44403, len 612) 21:36:34.085356 192.168.1.222.22222 > 192.168.4.205.49583: P 8730:9290(560) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 9562, len 612) 21:36:34.146233 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 2218 win 33280 (DF) [tos 0x10] (ttl 62, id 7984, len 52) 21:36:34.160008 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 3338 win 33024 (DF) [tos 0x10] (ttl 62, id 57938, len 52) 21:36:34.160390 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 47433, len 1500) 21:36:34.160572 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 7750, len 56) 21:36:34.172578 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 4458 win 33024 (DF) [tos 0x10] (ttl 62, id 49724, len 52) 21:36:34.172841 192.168.1.222.22222 > 192.168.4.205.49583: P 10738:11386(648) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 38939, len 700) 21:36:34.182182 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 5322 win 33024 (DF) [tos 0x10] (ttl 62, id 42, len 52) 21:36:34.192065 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 6186 win 33152 (DF) [tos 0x10] (ttl 62, id 50264, len 52) 21:36:34.204837 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 7306 win 33024 (DF) [tos 0x10] (ttl 62, id 10261, len 52) 21:36:34.214795 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 8170 win 33152 (DF) [tos 0x10] (ttl 62, id 23868, len 52) 21:36:34.227436 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 9290 win 33024 (DF) [tos 0x10] (ttl 62, id 33359, len 52) 21:36:34.260796 192.168.4.205.49583 > 192.168.1.222.22222: . [tcp sum ok] ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 45065, len 64) 21:36:34.646893 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 4163, len 1500) 21:36:34.647097 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 41082, len 56) 21:36:35.286923 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 16245, len 1500) 21:36:35.287123 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 62739, len 56) 21:36:36.367102 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 63541, len 1500) 21:36:36.367417 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 64556, len 56) 21:36:38.326892 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 51048, len 1500) 21:36:38.327099 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 57181, len 56) 21:36:51.158423 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 53795, len 64) 21:36:51.550391 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 19270, len 64) 21:36:52.046839 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 62304, len 1500) 21:36:52.047052 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 42608, len 56) 21:36:52.134031 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 64268, len 64) 21:36:53.101780 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 36677, len 64) 21:36:54.838137 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 1287, len 64) 21:36:54.838559 192.168.1.222.22222 > 192.168.4.205.49583: . 9290:10738(1448) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 7692, len 1500) 21:36:54.838740 192.168.1.1 > 192.168.1.222: icmp: 192.168.4.205 unreachable - need to frag (mtu 1280) (DF) (ttl 64, id 61241, len 56) 21:36:58.110409 192.168.4.205.49583 > 192.168.1.222.22222: F [tcp sum ok] 2536:2536(0) ack 9290 win 33304 (DF) [tos 0x10] (ttl 62, id 31752, len 64) 21:36:58.110745 192.168.1.222.22222 > 192.168.4.205.49583: P 11386:11530(144) ack 2536 win 33304 (DF) [tos 0x10] (ttl 64, id 26385, len 196) 21:36:58.173931 192.168.4.205.49583 > 192.168.1.222.22222: R [tcp sum ok] 894018857:894018857(0) win 0 (DF) (ttl 62, id 36985, len 40) --7ZAtKRhVyVSsbBD2--