On Fri, Sep 01, 2006 at 01:25:19PM +0200, Jeroen Massar wrote: > Tim Chown wrote: > >Hi, > > > >While I can establish a fast telnet session to port 80: > > > >$ telnet www.ietf.org 80 > >Trying 2001:503:c779:b::d1ad:35b4... > >Connected to www.ietf.org. > >Escape character is '^]'. > > > >Attempting to browse via MSIE leads to timeouts. > > > >Connecting explictly to http://209.173.53.180 to assure IPv4 works fine. > > "telnet -4 www.ietf.org" should do that trick too, but notez bien: > > www.ietf.org A 209.173.53.180 > www.ietf.org A 209.173.57.180 > www.ietf.org AAAA 2001:503:C779:B:0:0:D1AD:35B4 > > We don't know if those are 3 different boxes, or simply 1 box with > multiple links/addresses. As IPv4 traceroutes die off one can't tell > what really is happening behind AT&T (at least from my perspective). > Looking at routeviews it seems that both IPv4 /24's have somewhat > different ASPaths, going over different upstreams. > > >Perhaps some Apache issue or PMTU issue? > > Most likely PMTU. > > >Anyone else experiencing this? > > Works from boxes behind my home DSL line (purgatory.unfix.org) and from > my work box, which is behind SWITCH (2001:620::/32). Tested with telnet, > MSIE and firefox. See below for traces from the DSL. > > Can you try tracepath6, which is available afaik only on Linux boxes > though, to show the MTU path? (iputils-tracepath is the deb package) > > -- > jeroen@purgatory:~$ tracepath6 www.ietf.org > 1?: [LOCALHOST] pmtu 1480 > 1: 2001:7b8:5:10:74::1 32.572ms > 2: i49.ge-0-1-0.jun1.kelvin.ipv6.network.bit.nl asymm 3 33.623ms > 3: jun1.telecity.ipv6.network.bit.nl asymm 4 34.609ms > 4: zpr2.amt.cw.net asymm 5 35.522ms > 5: so-5-2-0-dcr1.amd.cw.net asymm 6 34.597ms > 6: as0-dcr2.amd.cw.net asymm 7 35.611ms > 7: so-4-0-0-dcr1.tsd.cw.net asymm 8 41.612ms > 8: so-1-0-0-zcr1.lnt.cw.net asymm 9 41.507ms > 9: 2001:7f8:4::31f9:1 asymm 8 137.537ms > 10: v3323-mpd.cr1.ewr1.us.occaid.net asymm 7 141.670ms > 11: ge-0-1-0.cr1.iad1.us.occaid.net asymm 7 146.538ms > 12: unknown.occaid.net asymm 8 152.466ms > > And then no responses, thus most likely filtered for this kind of trace. So I'm on RedHat, have tracepath6 installed (not used before, thanks for the pointer :) and I see in comparison: $ /usr/sbin/tracepath6 www.ietf.org 1?: [LOCALHOST] pmtu 1500 1: 2001:630:d0:f102::2 1.191ms 2: zaphod.6core.ecs.soton.ac.uk 1. 93ms 3: ford.6core.ecs.soton.ac.uk 1.915ms 4: 2001:630:c1:100::1 2. 66ms 5: 2001:630:c1:10::1 2.353ms 6: no reply 7: no reply 8: no reply 9: po9-0.cosh-scr.ja.net 8.440ms 10: po2-0.lond-scr.ja.net 5.273ms 11: po0-0.lond-scr4.ja.net 6.319ms 12: gi0-1.lond-isr4.ja.net 6.238ms 13: 2001:630:0:10::52 8.138ms 14: ge-2-24.r01.londen03.uk.bb.gin.ntt.net 11.163ms 15: xe-0-1-0.r23.londen03.uk.bb.gin.ntt.net asymm 16 11.525ms 16: xe-0-2-0.r22.londen03.uk.bb.gin.ntt.net asymm 17 15.225ms 17: 1d-uk6x.ipv6.btexact.com 11.292ms 18: 52.ge0-0.cr2.lhr1.uk.occaid.net 13.643ms 19: 52.ge0-0.cr2.lhr1.uk.occaid.net asymm 18 16. 63ms pmtu 1480 19: v3323-mpd.cr1.ewr1.us.occaid.net 88.237ms 20: ge-0-1-0.cr1.iad1.us.occaid.net 92.623ms 21: unknown.occaid.net 101.267ms 22: no reply 23: no reply 24: no reply 25: no reply 26: no reply 27: no reply 28: no reply 29: no reply 30: no reply 31: no reply Too many hops: pmtu 1480 Resume: pmtu 1480 Hmm, 1500 vs 1480. > But traceroute6 works fully: > > traceroute to www.ietf.org (2001:503:c779:b::d1ad:35b4) from > 2001:7b8:20d:0:290:27ff:fe24:c19f, 30 hops max, 24 byte packets > 1 2001:7b8:5:10:74::1 (2001:7b8:5:10:74::1) 13.874 ms 9.645 ms > 10.963 ms > 2 i49.ge-0-1-0.jun1.kelvin.ipv6.network.bit.nl > (2001:7b8:3:31:290:6900:31c6:d81f) 9.943 ms 15.581 ms 14.958 ms > 3 jun1.telecity.ipv6.network.bit.nl (2001:7b8::290:6900:1c6:7c1f) > 16.953 ms * 10.6 ms > 4 zpr2.amt.cw.net (2001:7f8:1::a500:1273:1) 10.972 ms 11.501 ms > 10.99 ms > 5 so-5-2-0-dcr1.amd.cw.net (2001:5000:0:12::1) 11.987 ms 11.614 ms > 11.986 ms > 6 as0-dcr2.amd.cw.net (2001:5000:0:11::2) 11.989 ms 11.569 ms > 10.989 ms > 7 so-4-0-0-dcr1.tsd.cw.net (2001:5000:0:20::2) 17.988 ms 17.589 ms > 17.989 ms > 8 so-1-0-0-zcr1.lnt.cw.net (2001:5000:0:61::2) 21.988 ms 17.505 ms > 17.988 ms > 9 2001:7f8:4::31f9:1 (2001:7f8:4::31f9:1) 112.99 ms 112.727 ms > 113.984 ms > 10 v3323-mpd.cr1.ewr1.us.occaid.net (2001:4830:fe:1010::2) 111.988 ms > 112.501 ms 112.991 ms > 11 ge-0-1-0.cr1.iad1.us.occaid.net (2001:4830:ff:f150::2) 117.969 ms > 118.47 ms 118.997 ms > 12 unknown.occaid.net (2001:4830:e6:d::2) 121.972 ms 122.48 ms > 121.978 ms > 13 stsc350a-eth3c0.va.neustar.com (2610:a0:c779::fe) 124.004 ms > 124.44 ms 124.975 ms > 14 2001:503:c779:b::d1ad:35b4 (2001:503:c779:b::d1ad:35b4) 123.992 ms > 122.722 ms 124.007 ms Likewise: $ /usr/sbin/traceroute6 www.ietf.org traceroute to www.ietf.org (2001:503:c779:b::d1ad:35b4) from 2001:630:d0:f102:230:48ff:fe23:58df, 30 hops max, 16 byte packets 1 2001:630:d0:f102::2 (2001:630:d0:f102::2) 1.883 ms 2.719 ms 4.513 ms 2 zaphod.6core.ecs.soton.ac.uk (2001:630:d0:f001::1) 4.462 ms 2.485 ms 2.886 ms 3 ford.6core.ecs.soton.ac.uk (2001:630:d0:f000::1) 3.444 ms 0.648 ms 0.64 ms 4 2001:630:c1:100::1 (2001:630:c1:100::1) 1.235 ms 1.104 ms 0.962 ms 5 2001:630:c1:10::1 (2001:630:c1:10::1) 1.21 ms 1.138 ms 1.186 ms 6 * * * 7 2001:630:c1::1 (2001:630:c1::1) 4.982 ms 2.891 ms 2.138 ms 8 2001:630:c1::1 (2001:630:c1::1) 2.562 ms 2.189 ms 2.662 ms 9 po9-0.cosh-scr.ja.net (2001:630:0:10::85) 6.928 ms 5.495 ms 2.477 ms 10 po2-0.lond-scr.ja.net (2001:630:0:10::29) 4.459 ms 4.32 ms 4.166 ms 11 po0-0.lond-scr4.ja.net (2001:630:0:10::56) 4.739 ms 4.51 ms 4.492 ms 12 gi0-1.lond-isr4.ja.net (2001:630:0:10::12a) 4.739 ms 4.384 ms 4.721 ms 13 2001:630:0:10::52 (2001:630:0:10::52) 6.307 ms 5.528 ms 4.987 ms 14 ge-2-24.r01.londen03.uk.bb.gin.ntt.net (2001:728:1c00:5000::9) 5.8 ms 5.663 ms 6.625 ms 15 xe-0-1-0.r23.londen03.uk.bb.gin.ntt.net (2001:728:0:2000::21) 6.66 ms 6.656 ms 6.885 ms 16 xe-0-2-0.r22.londen03.uk.bb.gin.ntt.net (2001:418:0:2000::1c9) 6.114 ms 6.369 ms 6.042 ms 17 1d-uk6x.ipv6.btexact.com (2001:7f8:2:1::1d) 7.595 ms 6.708 ms 6.703 ms 18 52.ge0-0.cr2.lhr1.uk.occaid.net (2001:4830:fe:1100::2) 11.047 ms 6.983 ms 8.301 ms 19 v3323-mpd.cr1.ewr1.us.occaid.net (2001:4830:fe:1010::2) 81.249 ms 82.56 ms 80.423 ms 20 ge-0-1-0.cr1.iad1.us.occaid.net (2001:4830:ff:f150::2) 87.17 ms 87.134 ms 85.887 ms 21 unknown.occaid.net (2001:4830:e6:d::2) 90.419 ms 90.738 ms 91.462 ms 22 stsc350a-eth3c0.va.neustar.com (2610:a0:c779::fe) 92.066 ms 92.392 ms 92.732 ms 23 2001:503:c779:b::d1ad:35b4 (2001:503:c779:b::d1ad:35b4) 91.799 ms 92.663 ms 90.864 ms -- Tim/::1 _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf