do the test from stanford node: [columbia4@planetlab-1 columbia4]$ uname -a Linux planetlab-1.stanford.edu 2.4.19-6_planetlab #2 Mon Aug 11 22:25:39 UTC 200 3 i686 unknown [columbia4@planetlab-1 columbia4]$ /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 171.64.64.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default Gates-gateway-2 0.0.0.0 UG 0 0 0 eth0 [columbia4@planetlab-1 columbia4]$ ping -Q 0x06 128.59.19.191 PING 128.59.19.191 (128.59.19.191) from 171.64.64.216 : 56(84) bytes of data. 64 bytes from 128.59.19.191: icmp_seq=1 ttl=238 time=86.7 ms 64 bytes from 128.59.19.191: icmp_seq=2 ttl=238 time=86.7 ms 64 bytes from 128.59.19.191: icmp_seq=3 ttl=238 time=86.9 ms 64 bytes from 128.59.19.191: icmp_seq=4 ttl=238 time=86.9 ms 64 bytes from 128.59.19.191: icmp_seq=5 ttl=238 time=86.7 ms 64 bytes from 128.59.19.191: icmp_seq=6 ttl=238 time=86.9 ms 64 bytes from 128.59.19.191: icmp_seq=7 ttl=238 time=86.9 ms --- 128.59.19.191 ping statistics --- 7 packets transmitted, 7 received, 0% loss, time 6078ms rtt min/avg/max/mdev = 86.700/86.855/86.993/0.249 ms [columbia4@planetlab-1 columbia4]$ [columbia4@planetlab-1 columbia4]$ /usr/sbin/traceroute 128.59.19.191 traceroute to 128.59.19.191 (128.59.19.191), 30 hops max, 38 byte packets 1 Gates-gateway-2.Stanford.EDU (171.64.64.1) 1.889 ms 1.090 ms 1.060 ms 2 bbr2-rtr.Stanford.EDU (171.64.1.161) 1.082 ms 1.889 ms 1.344 ms 3 dc1-rtr.Stanford.EDU (171.64.1.132) 1.838 ms 1.509 ms 1.517 ms 4 dc-svl-dc1--stan-ge.cenic.net (137.164.23.37) 3.054 ms 1.808 ms 1.951 ms 5 dc-sol-dc1--svl-dc1-pos.cenic.net (137.164.22.28) 3.006 ms 8.197 ms 4.296 ms 6 dc-slo-dc1--sol-dc2-pos.cenic.net (137.164.22.26) 9.318 ms 9.505 ms 9.256 ms 7 hpr-lax-hpr1--dc-lax-dc1-ge.cenic.net (137.164.22.13) 13.328 ms 9.447 ms 9.457 ms 8 abilene-LA--hpr-lax-gsr1-10ge.cenic.net (137.164.25.3) 9.321 ms 9.222 ms 9.586 ms 9 snvang-losang.abilene.ucaid.edu (198.32.8.95) 19.186 ms 17.101 ms 19.795 ms 10 kscyng-snvang.abilene.ucaid.edu (198.32.8.103) 52.613 ms 155.325 ms 119.7 73 ms 11 iplsng-kscyng.abilene.ucaid.edu (198.32.8.80) 343.617 ms 335.292 ms 318.4 87 ms 12 chinng-iplsng.abilene.ucaid.edu (198.32.8.76) 65.974 ms 65.156 ms 72.890 ms 13 buf-m20-abilene-chin.nysernet.net (199.109.2.1) 77.547 ms 77.769 ms 78.22 3 ms 14 roc-m10-buf-m20.nysernet.net (199.109.6.1) 79.595 ms 79.449 ms 78.994 ms 15 nyc-m20-roc-m10.nysernet.net (199.109.5.54) 87.631 ms 86.701 ms 87.067 ms 16 columbia-nyc-m20.nysernet.net (199.109.5.5) 87.242 ms 86.710 ms 87.226 ms 17 mudd-edge-1-vlan501-1.net.columbia.edu (128.59.1.41) 87.069 ms 87.012 ms 87.453 ms 18 bart.cs.columbia.edu (128.59.19.191) 87.639 ms 87.457 ms 87.381 ms [columbia4@planetlab-1 columbia4]$ //----------------------------------------------------------------------------------------------------------- : bart.cs.columbia.edu ;netstat -rn Routing Table: IPv4 Destination Gateway Flags Ref Use Interface -------------------- -------------------- ----- ----- ------ --------- 128.59.16.0 128.59.19.191 U 1 19701 hme0 224.0.0.0 128.59.19.191 U 1 0 hme0 default 128.59.16.1 UG 1 43636 127.0.0.1 127.0.0.1 UH 37522929 lo0 Routing Table: IPv6 Destination/Mask Gateway Flags Ref Use If --------------------------- --------------------------- ----- --- ------ ----- 2001:468:904:16::/64 2001:468:904:16:a00:20ff:feab:d50d U 1 690 hme0:1 fe80::/10 fe80::a00:20ff:feab:d50d U 1 74 hme0 ff00::/8 fe80::a00:20ff:feab:d50d U 1 0 hme0 default fe80::260:3eff:fe3f:1a20 UG 1 0 hme0 ::1 ::1 UH 2 112860 lo0 : bart.cs.columbia.edu ;uname -a SunOS bart.cs.columbia.edu 5.8 Generic_108528-21 sun4u sparc SUNW,Ultra-5_10 : bart.cs.columbia.edu ; : bart.cs.columbia.edu ;tcpdump -n -v -v tcpdump: listening on hme0 15:15:52.908518 171.64.64.216 > 128.59.19.191: icmp: echo request (DF) [tos 0x6,ECT(0)] (ttl 47, id 0, len 84) 15:15:52.908550 128.59.19.191 > 171.64.64.216: icmp: echo reply (DF) [tos 0x6,ECT(0)] (ttl 255, id 28384, len 84) from stanford, the TOS retain the same. //------------------------------------------------------------------------------------------------------------------- //------------------------------------------------------------------------------------------------------------------- do the test from HP node [columbia4@pli2-pa-1 columbia4]$ uname -a Linux pli2-pa-1.hpl.hp.com 2.4.19-6_planetlab #2 Mon Aug 11 22:25:39 UTC 2003 i6 86 unknown [columbia4@pli2-pa-1 columbia4]$ /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.6.26.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default 192.6.26.1 0.0.0.0 UG 0 0 0 eth0 [columbia4@pli2-pa-1 columbia4]$ /usr/sbin/traceroute 128.59.19.191 traceroute to 128.59.19.191 (128.59.19.191), 30 hops max, 38 byte packets 1 192.6.26.1 (192.6.26.1) 0.557 ms 0.525 ms 0.405 ms 2 171.66.1.17 (171.66.1.17) 1.073 ms 1.037 ms 0.910 ms 3 i2-gateway.Stanford.EDU (171.64.1.217) 0.900 ms 0.950 ms 0.918 ms 4 dc-oak-dc1--stan-ge.cenic.net (137.164.23.41) 2.391 ms 2.407 ms 2.269 ms 5 dc-oak-dc2--oak-dc1-ge.cenic.net (137.164.22.37) 2.516 ms 2.245 ms 2.828 ms 6 dc-csac-dc1--oak-dc2-ge.cenic.net (137.164.22.111) 4.536 ms 4.369 ms 4.50 6 ms 7 dc-lax-dc1--sac-dc1-pos.cenic.net (137.164.22.126) 13.786 ms 13.755 ms 13 .710 ms 8 hpr-lax-hpr1--dc-lax-dc1-ge.cenic.net (137.164.22.13) 14.132 ms 14.069 ms 14.125 ms 9 abilene-LA--hpr-lax-gsr1-10ge.cenic.net (137.164.25.3) 17.556 ms 22.830 ms 13.694 ms 10 snvang-losang.abilene.ucaid.edu (198.32.8.95) 12.699 ms 15.843 ms 12.563 ms 11 kscyng-snvang.abilene.ucaid.edu (198.32.8.103) 54.914 ms 47.932 ms 48.250 ms 12 iplsng-kscyng.abilene.ucaid.edu (198.32.8.80) 311.632 ms 323.574 ms 330.3 96 ms 13 chinng-iplsng.abilene.ucaid.edu (198.32.8.76) 60.904 ms 60.692 ms 63.329 ms 14 buf-m20-abilene-chin.nysernet.net (199.109.2.1) 73.234 ms 73.291 ms 73.69 6 ms 15 roc-m10-buf-m20.nysernet.net (199.109.6.1) 74.835 ms 74.681 ms 74.738 ms 16 nyc-m20-roc-m10.nysernet.net (199.109.5.54) 82.333 ms 82.276 ms 82.213 ms 17 columbia-nyc-m20.nysernet.net (199.109.5.5) 82.875 ms 86.483 ms 123.541 m s 18 mudd-edge-1-vlan501-1.net.columbia.edu (128.59.1.41) 83.360 ms 83.095 ms 83.661 ms 19 bart.cs.columbia.edu (128.59.19.191) 82.930 ms 83.166 ms 83.476 ms [columbia4@pli2-pa-1 columbia4]$ [columbia4@pli2-pa-1 columbia4]$ ping -Q 0x06 128.59.19.191 PING 128.59.19.191 (128.59.19.191) from 192.6.26.31 : 56(84) bytes of data. 64 bytes from 128.59.19.191: icmp_seq=1 ttl=239 time=82.7 ms 64 bytes from 128.59.19.191: icmp_seq=2 ttl=239 time=83.1 ms 64 bytes from 128.59.19.191: icmp_seq=3 ttl=239 time=83.0 ms --- 128.59.19.191 ping statistics --- 3 packets transmitted, 3 received, 0% loss, time 2015ms rtt min/avg/max/mdev = 82.797/82.976/83.125/0.135 ms [columbia4@pli2-pa-1 columbia4]$ //------------------------------------------------------------------------------------ : bart.cs.columbia.edu ;tcpdump -n -v -v tcpdump: listening on hme0 15:28:00.109780 192.6.26.31 > 128.59.19.191: icmp: echo request (DF) [tos 0x6,ECT(0)] (ttl 46, id 0, len 84) 15:28:00.109811 128.59.19.191 > 192.6.26.31: icmp: echo reply (DF) [tos 0x6,ECT(0)] (ttl 255, id 15533, len 84) from HP node, the TOS retain the same. //------------------------------------------------------------------------------------------------------------------- //------------------------------------------------------------------------------------------------------------------- do the test from Technische Universitat Berlin Technische node [columbia4@edi columbia4]$ uname -a Linux edi.tkn.tu-berlin.de 2.4.19-6_planetlab #2 Mon Aug 11 22:25:39 UTC 2003 i6 86 unknown [columbia4@edi columbia4]$ /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 130.149.49.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default ssr86-EN.gate.T 0.0.0.0 UG 0 0 0 eth0 [columbia4@edi columbia4]$ /usr/sbin/traceroute 128.59.19.191 traceroute to 128.59.19.191 (128.59.19.191), 30 hops max, 38 byte packets 1 ssr86-EN.gate.TU-Berlin.DE (130.149.49.1) 1.359 ms 1.333 ms 1.244 ms 2 ssr8-EN.gate.TU-Berlin.DE (130.149.8.21) 1.209 ms 2.076 ms 1.236 ms 3 ssr8pos-EN.gate.TU-Berlin.DE (130.149.0.13) 1.461 ms 1.404 ms 2.423 ms 4 ar-tuberlin1.g-win.dfn.de (188.1.33.65) 1.455 ms 1.501 ms 1.432 ms 5 cr-berlin1-po4-1.g-win.dfn.de (188.1.20.9) 3.145 ms 13.854 ms 2.488 ms 6 cr-frankfurt1-po9-2.g-win.dfn.de (188.1.18.185) 11.647 ms 10.679 ms 11.11 2 ms 7 ir-frankfurt2-po3-0.g-win.dfn.de (188.1.80.42) 12.246 ms 10.874 ms 11.271 ms 8 dfn.de1.de.geant.net (62.40.103.33) 11.664 ms 11.557 ms 11.224 ms 9 de1-2.de2.de.geant.net (62.40.96.53) 11.776 ms 11.880 ms 11.275 ms 10 abilene-gw.de2.de.geant.net (62.40.103.254) 105.440 ms 105.202 ms 105.780 ms 11 nycmng-washng.abilene.ucaid.edu (198.32.8.84) 102.047 ms 101.675 ms 107.3 39 ms 12 nyc-m20-abilene-nycm.nysernet.net (199.109.5.1) 124.624 ms 112.909 ms 114 .563 ms 13 columbia-nyc-m20.nysernet.net (199.109.5.5) 110.035 ms 108.876 ms 108.906 ms 14 mudd-edge-1-vlan501-1.net.columbia.edu (128.59.1.41) 109.446 ms 112.545 ms 119.801 ms 15 bart.cs.columbia.edu (128.59.19.191) 119.664 ms 111.491 ms 113.645 ms [columbia4@edi columbia4]$ ping -Q 0x06 128.59.19.191 PING 128.59.19.191 (128.59.19.191) from 130.149.49.26 : 56(84) bytes of data. 64 bytes from 128.59.19.191: icmp_seq=1 ttl=240 time=103 ms 64 bytes from 128.59.19.191: icmp_seq=2 ttl=240 time=102 ms 64 bytes from 128.59.19.191: icmp_seq=3 ttl=240 time=112 ms 64 bytes from 128.59.19.191: icmp_seq=4 ttl=240 time=105 ms --- 128.59.19.191 ping statistics --- 4 packets transmitted, 4 received, 0% loss, time 3014ms rtt min/avg/max/mdev = 102.323/106.028/112.384/3.875 ms [columbia4@edi columbia4]$ [columbia4@edi columbia4]$ //------------------------------------------------------------------------------------------------ : bart.cs.columbia.edu ;tcpdump -n -v -v tcpdump: listening on hme0 15:36:40.655587 130.149.49.26 > 128.59.19.191: icmp: echo request (DF) [tos 0x6,ECT(0)] (ttl 50, id 0, len 84) 15:36:40.655619 128.59.19.191 > 130.149.49.26: icmp: echo reply (DF) [tos 0x6,ECT(0)] (ttl 255, id 15044, len 84) from Technische Universitat Berlin Technische, the TOS retain the same. //------------------------------------------------------------------------------------------------ then use trace route from the receiver to sender, we could find all packet come from the gateway of nn2k-gw.net.columbia.edu [128.59.1.6],Internet2 gateway. Tracing route to planetlab-1.Stanford.EDU [171.64.64.216] over a maximum of 30 hops: 1 <1 ms <1 ms <1 ms 128.59.128.1 2 24 ms 8 ms 4 ms nn2k-gw.net.columbia.edu [128.59.1.6] 3 1 ms 1 ms <1 ms nyc-m20-columbia.nysernet.net [199.109.5.6] 4 8 ms 8 ms 8 ms roc-m10-nyc-m20.nysernet.net [199.109.5.53] 5 10 ms 10 ms 10 ms buf-m20-roc-m10.nysernet.net [199.109.6.2] 6 22 ms 22 ms 22 ms abilene-chin-buf-m20.nysernet.net [199.109.2.2] 7 293 ms 297 ms * iplsng-chinng.abilene.ucaid.edu [198.32.8.77] 8 35 ms 36 ms 35 ms kscyng-iplsng.abilene.ucaid.edu [198.32.8.81] 9 70 ms 70 ms 70 ms snvang-kscyng.abilene.ucaid.edu [198.32.8.102] 10 86 ms 78 ms 78 ms losang-snvang.abilene.ucaid.edu [198.32.8.94] 11 78 ms 77 ms 78 ms hpr-lax-gsr1--abilene-LA-10ge.cenic.net [137.164.25.2] 12 80 ms 78 ms 78 ms dc-lax-dc1--lax-hpr1-ge.cenic.net [137.164.22.12] 13 84 ms 84 ms 84 ms dc-sol-dc2--slo-dc1-pos.cenic.net [137.164.22.27] 14 86 ms 85 ms 85 ms dc-svl-dc1--sol-dc1-pos.cenic.net [137.164.22.29] 15 86 ms 86 ms 86 ms dc-stan--svl-dc1-ge.cenic.net [137.164.23.38] 16 87 ms 86 ms 87 ms bbr2-rtr.Stanford.EDU [171.64.1.133] 17 86 ms 87 ms 86 ms Gates-rtr.Stanford.EDU [171.64.1.178] 18 87 ms 86 ms 87 ms planetlab-1.Stanford.EDU [171.64.64.216] Trace complete. Tracing route to pli2-pa-1.hpl.hp.com [192.6.26.31] over a maximum of 30 hops: 1 <1 ms <1 ms <1 ms 128.59.128.1 2 <1 ms <1 ms <1 ms nn2k-gw.net.columbia.edu [128.59.1.6] 3 1 ms 1 ms 1 ms nyc-m20-columbia.nysernet.net [199.109.5.6] 4 8 ms 8 ms 8 ms roc-m10-nyc-m20.nysernet.net [199.109.5.53] 5 10 ms 10 ms 10 ms buf-m20-roc-m10.nysernet.net [199.109.6.2] 6 22 ms 22 ms 22 ms abilene-chin-buf-m20.nysernet.net [199.109.2.2] 7 284 ms 300 ms 285 ms iplsng-chinng.abilene.ucaid.edu [198.32.8.77] 8 47 ms 35 ms 35 ms kscyng-iplsng.abilene.ucaid.edu [198.32.8.81] 9 70 ms 70 ms 78 ms snvang-kscyng.abilene.ucaid.edu [198.32.8.102] 10 70 ms 70 ms 70 ms 198.32.249.161 11 71 ms 71 ms 71 ms BERK--SUNV.POS.calren2.net [198.32.249.13] 12 71 ms 71 ms 72 ms UCOP--BERK.POS.calren2.net [198.32.249.10] 13 81 ms 80 ms 81 ms dc-oak-dc1--c2-ucop-gsr-ge.cenic.net [137.164.22.84] 14 82 ms 82 ms 82 ms dc-stan--oak-dc1-ge.cenic.net [137.164.23.42] 15 82 ms 82 ms 82 ms mcast-gateway-2.Stanford.EDU [171.64.1.218] 16 82 ms 83 ms 82 ms 171.66.1.20 17 83 ms 83 ms 83 ms pli2-pa-1.hpl.hp.com [192.6.26.31] Trace complete. Tracing route to edi.tkn.TU-Berlin.DE [130.149.49.26] over a maximum of 30 hops: 1 <1 ms <1 ms <1 ms 128.59.128.1 2 <1 ms <1 ms <1 ms nn2k-gw.net.columbia.edu [128.59.1.6] 3 1 ms <1 ms 1 ms nyc-m20-columbia.nysernet.net [199.109.5.6] 4 2 ms 2 ms 2 ms abilene-nycm-nyc-m20.nysernet.net [199.109.5.2] 5 1 ms 1 ms 2 ms 198.32.11.62 6 70 ms 70 ms 71 ms ny.uk1.uk.geant.net [62.40.96.170] 7 101 ms 100 ms 100 ms uk.nl1.nl.geant.net [62.40.96.181] 8 94 ms 95 ms 93 ms nl.de1.de.geant.net [62.40.96.101] 9 91 ms 95 ms 92 ms ir-frankfurt2-po4-0.g-win.dfn.de [62.40.103.34] 10 92 ms 96 ms 98 ms cr-frankfurt1-po3-0.g-win.dfn.de [188.1.80.41] 11 100 ms 100 ms 101 ms cr-berlin1-po2-2.g-win.dfn.de [188.1.18.186] 12 108 ms 104 ms 102 ms ar-tuberlin1-po0-0.g-win.dfn.de [188.1.20.10] 13 101 ms 104 ms 103 ms ssr8pos-EN.gate.TU-Berlin.DE [130.149.0.5] 14 103 ms 103 ms 106 ms ssr8-EN.gate.TU-Berlin.DE [130.149.0.14] 15 101 ms 111 ms 113 ms ssr86-EN.gate.TU-Berlin.DE [130.149.8.1] 16 102 ms 104 ms 104 ms edi.tkn.TU-Berlin.DE [130.149.49.26] Trace complete. So, from the results, we could say, if the packet come and out from the nn2k-gw.net.columbia.edu [128.59.1.6],Internet2 gateway, the TOS seems bits will not lost. ( I already did the test from sender to receriver, and used tcpdump at sender last time , while this time use tcpdump at receiver to verify the results)