Forum - Packet loss on tunnel :: SixXS - IPv6 Deployment & Tunnel Broker

Packet loss on tunnel

Shadow Hawkins on Thursday, 19 March 2009 00:04:57

Hi, I'm trying to setup my tunnel, and, at first glance it seems to be working well. I got an IPv6 address and I've been able to connect out to other IPv6 hosts. But at the same time, by tunnel statistics from the sixxs.net tunnelinfo page shows loss statistics varying from 20% to 100% since the time I established the tunnel. Similarly, if I try to use the traceroute utility here: https://www.sixxs.net/tools/traceroute/ to try to traceroute to my IPv6 address, I see about 25% loss on the last hop between the "Eweka Internet Services" and my IPv6 address. 10. 2001:4de0:1000:a5::2 0.0% 5 181.2 185.0 181.2 199.6 8.2 [.nl] Netherlands, The 12989 Eweka Internet Services 11. 2001:1938:82:70::2 20.0% 5 212.1 210.3 203.3 222.3 9.0 [.us] United States 12989 Highwinds Network Group Inc Strangely, if I just ping6 the same address in hop 10, I see no loss: I'm using ubuntu linux, and have the tunnel configured in my interfaces file like: auto sixxs iface sixxs inet6 v4tunnel address 2001:1938:82:70::2 netmask 64 endpoint 209.197.4.66 ttl 64 up ip link set mtu 1280 dev sixxs up ip route add default via 2001:1938:82:70::1 I suspect I might have some sort of routing problem, but am scratching my head. Here's my output from route: chris@k9[109]:~% route -6 Kernel IPv6 routing table Destination Next Hop Flag Met Ref Use If ::1/128 :: Un 0 1 61 lo 2001:1938:82:70::2/128 :: Un 0 1 41 lo 2001:1938:82:70::2/128 :: !n 1024 0 3 lo 2001:1938:82:70::/64 :: Un 256 0 1 sixxs fe80::40ae:22fb/128 :: Un 0 1 0 lo fe80::c0a8:5501/128 :: Un 0 1 0 lo fe80::21f:d0ff:fe8e:482d/128 :: Un 0 1 0 lo fe80::21f:d0ff:fe8e:482d/128 :: Un 0 1 0 lo fe80::221:91ff:fe19:8a34/128 :: Un 0 1 0 lo fe80::acb8:81ff:fe76:952b/128 :: Un 0 1 0 lo fe80::e0c7:84ff:feed:2417/128 :: Un 0 1 0 lo fe80::e0cb:3cff:fe09:f25c/128 :: Un 0 1 0 lo fe80::/64 :: U 256 0 0 eth1 fe80::/64 :: U 256 0 0 br0 fe80::/64 :: U 256 0 0 eth0 fe80::/64 :: U 256 0 0 tap4 fe80::/64 :: U 256 0 0 tap5 fe80::/64 :: U 256 0 0 tap6 fe80::/64 :: Un 256 0 0 sixxs ff00::/8 :: U 256 0 0 eth1 ff00::/8 :: U 256 0 0 br0 ff00::/8 :: U 256 0 0 eth0 ff00::/8 :: U 256 0 0 tap4 ff00::/8 :: U 256 0 0 tap5 ff00::/8 :: U 256 0 0 tap6 ff00::/8 :: U 256 0 0 sixxs ::/0 2001:1938:82:70::1 UG 1024 0 42 sixxs ::/0 :: !n -1 1 1 lo Anyone have any idea what might be wrong, or some advice on how to troubleshoot this? Thanks! Chris

Packet loss on tunnel

Jeroen Massar SixXS Staff

on Thursday, 19 March 2009 00:47:49

2001:1938:82:70::2/128 :: Un 0 1 41 lo

2001:1938:82:70::2/128 :: !n 1024 0 3 lo

Those two look fishy, I think you only need the first one, not the second one (which would reject with icmp unreachable any packet to ::2, it has the highest metric thus wins) Next to that it seems you have a lot of interfaces, are you sure your tunnel 'local' portion is correct? BTW: 'ip' is the tool nowadays to use, not 'route'. Then again, 'ip ro sho' needs special flags to show those two entries above. As for the traceroute, what is the full traceroute? Showing two hops out of a very large set is not a useful thing, especially without knowing source+dest. Also note that packetloss might be happening on the IPv4 level; there have been reports that some ISPs do "QoS" for unknown packets (read: port 80 is great, anything else only gets through when they feel like it).

Packet loss on tunnel

Shadow Hawkins on Thursday, 19 March 2009 16:55:52

Thanks for the ideas. Deleting the route didn't seem to make a difference. And I'm not really sure how that route ever got there -- when I stopped and restarted the interface it never showed up again. Here's the full traceroute: IPv6 traceroute from noc.sixxs.net @ SixXS NOC, AS12871 to 2001:1938:82:70::2 : Hop Node Loss% Sent Last Avg Best Worst StDev ASN Organisation 1. 2001:838:1:1::1 0.0% 5 0.4 0.4 0.4 0.5 0.0 [.nl] Netherlands, The 12871 Concepts ICT ge-1-3-0.breda.ipv6.concepts-ict.net. 2. 2001:838:0:10::1 0.0% 5 2.4 2.6 2.4 3.1 0.3 [.nl] Netherlands, The 12871 Concepts ICT 3. 2001:838:5:4::2 0.0% 5 2.5 31.2 2.2 146.2 64.3 [.nl] Netherlands, The 12871 Concepts ICT 4. 2001:7f8:1::a501:2989:1 0.0% 5 3.2 4.9 3.1 11.2 3.5 [.nl] Netherlands, The AMS-IX-IPV6 ams-ix.hwng.net. 5. 2001:4de0:1000:1::1 0.0% 5 3.2 3.3 3.0 3.9 0.3 [.nl] Netherlands, The 12989 Eweka Internet Services 5-1.r1.am.v6.hwng.net. 6. 2001:4de0:1000:4::2 0.0% 5 109.3 103.4 99.9 109.3 4.6 [.nl] Netherlands, The 12989 Eweka Internet Services 1-1.r1.dc.v6.hwng.net. 7. 2001:4de0:1000:11::1 0.0% 5 105.5 109.7 105.5 116.8 5.6 [.nl] Netherlands, The 12989 Eweka Internet Services 1-2.r1.ny.v6.hwng.net. 8. 2001:4de0:1000:13::2 0.0% 5 125.9 126.0 125.9 126.2 0.1 [.nl] Netherlands, The 12989 Eweka Internet Services 3-1.r1.ch.v6.hwng.net. 9. 2001:4de0:1000:17::2 0.0% 5 181.2 181.4 181.2 181.6 0.1 [.nl] Netherlands, The 12989 Eweka Internet Services 1-1.r1.la.v6.hwng.net. 10. 2001:4de0:1000:a5::2 0.0% 5 181.2 181.5 181.2 181.8 0.2 [.nl] Netherlands, The 12989 Eweka Internet Services 11. 2001:1938:82:70::2 20.0% 5 203.7 203.5 202.7 203.9 0.6 [.us] United States 12989 Highwinds Network Group Inc And if I do the same from my machine in the reverse direction: chris@k9[14]:~% traceroute -N16 -q10 -6 2001:838:1:1::1 traceroute to 2001:838:1:1::1 (2001:838:1:1::1), 30 hops max, 40 byte packets 1 gw-113.lax-01.us.sixxs.net (2001:1938:82:70::1) 25.840 ms 28.721 ms 32.109 ms 35.725 ms 38.892 ms 42.052 ms * * * * 2 2001:4de0:1000:a5::1 (2001:4de0:1000:a5::1) 59.326 ms 61.703 ms 65.114 ms 68.263 ms 71.660 ms 83.699 ms 57.546 ms 57.708 ms 56.533 ms 56.044 ms 3 1-1.r1.sj.v6.hwng.net (2001:4de0:1000:18::1) 63.928 ms 64.171 ms 59.293 ms 58.325 ms 55.861 ms 53.879 ms 51.928 ms 42.040 ms 44.039 ms 57.083 ms 4 1-1.r2.dc.v6.hwng.net (2001:4de0:1000:19::2) 128.803 ms 129.285 ms 121.643 ms 121.164 ms 121.641 ms 123.863 ms 126.323 ms 128.309 ms 129.533 ms 130.765 ms 5 2-3.r1.dc.v6.hwng.net (2001:4de0:1000:9::1) 134.461 ms 121.638 ms 119.175 ms 116.719 ms 114.255 ms 112.767 ms 109.554 ms 117.952 ms 115.727 ms 113.506 ms 6 1-1.r1.am.v6.hwng.net (2001:4de0:1000:4::1) 207.882 ms 207.383 ms 206.894 ms 209.122 ms 207.617 ms 209.608 ms 211.577 ms 213.792 ms 207.389 ms 207.142 ms 7 2001:4de0:1000:a13::2 (2001:4de0:1000:a13::2) 212.321 ms 214.773 ms 210.081 ms 211.085 ms 209.601 ms 210.334 ms 210.098 ms 210.104 ms 211.078 ms 210.349 ms 8 jointtransit.ip6.concepts-ict.nl (2a02:10:0:2::4) 207.886 ms 207.131 ms 207.388 ms 207.397 ms 207.630 ms 208.375 ms 208.118 ms 207.638 ms 207.612 ms 208.116 ms 9 2001:838:5:4::1 (2001:838:5:4::1) 201.726 ms 202.218 ms 203.695 ms 200.241 ms 200.490 ms 200.231 ms 200.479 ms 200.475 ms 200.981 ms 200.670 ms 10 ge-1-3-0.breda.ipv6.concepts-ict.net (2001:838:1:1::1) 207.377 ms 209.358 ms 211.577 ms 211.574 ms 208.615 ms 204.920 ms 205.663 ms 208.348 ms 207.886 ms 211.576 ms If I run a V4 traceroute to the tunnel's IPv4 endpoint, it shows a lot of loss on the last hop. chris@k9[18]:~% traceroute 209.197.4.66 traceroute to 209.197.4.66 (209.197.4.66), 30 hops max, 40 byte packets 1 adsl-64-174-34-249.dsl.snfc21.pacbell.net (64.174.34.249) 15.466 ms 18.359 ms 22.261 ms 2 dist2-vlan52.snfcca.sbcglobal.net (206.13.3.66) 25.417 ms 28.592 ms 31.772 ms 3 bb2-10g2-0.snfcca.sbcglobal.net (216.102.176.226) 35.678 ms 38.614 ms 41.766 ms 4 151.164.95.246 (151.164.95.246) 46.665 ms 49.847 ms 53.508 ms 5 64.215.195.241 (64.215.195.241) 56.926 ms 59.843 ms 63.030 ms 6 162.97.117.2 (162.97.117.2) 75.305 ms 25.471 ms 25.108 ms 7 209.197.4.66 (209.197.4.66) 28.299 ms 31.714 ms 35.359 ms chris@k9[19]:~% traceroute 209.197.4.66 traceroute to 209.197.4.66 (209.197.4.66), 30 hops max, 40 byte packets 1 adsl-64-174-34-249.dsl.snfc21.pacbell.net (64.174.34.249) 10.136 ms 13.277 ms 16.206 ms 2 dist2-vlan52.snfcca.sbcglobal.net (206.13.3.66) 20.359 ms 23.292 ms 26.451 ms 3 bb2-10g2-0.snfcca.sbcglobal.net (216.102.176.226) 29.873 ms 33.039 ms 36.221 ms 4 151.164.95.246 (151.164.95.246) 41.366 ms 44.772 ms 47.705 ms 5 64.215.195.241 (64.215.195.241) 51.365 ms 54.550 ms 57.724 ms 6 162.97.117.2 (162.97.117.2) 70.000 ms 77.410 ms 76.494 ms 7 209.197.4.66 (209.197.4.66) 78.215 ms 76.806 ms * chris@k9[20]:~% traceroute -q10 209.197.4.66 traceroute to 209.197.4.66 (209.197.4.66), 30 hops max, 40 byte packets 1 adsl-64-174-34-249.dsl.snfc21.pacbell.net (64.174.34.249) 9.567 ms 18.116 ms 21.530 ms 24.700 ms 28.369 ms 31.050 ms 34.711 ms 38.151 ms 41.053 ms 44.481 ms 2 dist2-vlan52.snfcca.sbcglobal.net (206.13.3.66) 48.390 ms 51.073 ms 54.991 ms 57.668 ms 61.818 ms 64.253 ms 59.634 ms 64.993 ms 64.888 ms 68.579 ms 3 bb2-10g2-0.snfcca.sbcglobal.net (216.102.176.226) 68.108 ms 68.605 ms 68.124 ms 68.217 ms 68.603 ms 68.600 ms 66.704 ms 68.324 ms 67.855 ms 68.359 ms 4 151.164.95.246 (151.164.95.246) 135.880 ms 133.912 ms 128.237 ms 116.431 ms 113.699 ms 107.287 ms 103.880 ms 102.106 ms 99.395 ms 96.232 ms 5 64.215.195.241 (64.215.195.241) 55.054 ms 54.796 ms 54.561 ms 54.323 ms 55.060 ms 96.665 ms 61.501 ms 61.276 ms 61.772 ms 62.263 ms 6 162.97.117.2 (162.97.117.2) 72.867 ms 60.305 ms 77.118 ms 77.207 ms 77.445 ms 77.472 ms 78.150 ms 80.870 ms 83.637 ms 86.834 ms 7 209.197.4.66 (209.197.4.66) 108.311 ms 92.774 ms 92.542 ms 93.029 ms 93.282 ms 92.542 ms * * * * Since the loss is showing up on V4 at the tunnel's V4 endpoint, maybe this is a problem with the tunnel? Thanks for your help, Chris

Packet loss on tunnel

Shadow Hawkins on Thursday, 19 March 2009 21:11:03

I am no expert but fools rush in... Does aiccu test ever give any errors? It doesn't for me but my stats always show losses. I was attributing that to my NAT router which passes traffic correctly if initiated locally but doesn't always forward to the right machine otherwise. I have several aiccu Windows clients, they all work fine although Ubuntu is the DMZ that keeps the tunnel alive.

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