为什么选播服务器太远/太慢? BGP选播如何工作?

我试过对Rage4的DNS服务器做一些traceroutetesting,这些testing是从世界上许多地方(据说是从30个不同的地方 )发布的。

我所经历的是,traceroute经常显示被联系的服务器离查询位置很远,即使来自另一个位置的traceroute会显示一个本应该非常接近的服务器。

例如,从法国,我们要去印度服务器:

 traceroute到ns2.r4ns.com(176.124.113.200),最多16跳,60字节的数据包
  1 88-190-61-1.poneytelecom.eu(88.190.61.1)[AS12322] 2.695ms 2.876ms 3.000ms
  2 a9k2-1041.dc3.poneytelecom.eu(88.191.1.185)[AS12322] 1.178 ms 1.447 ms 1.516 ms
  3 ix-25-0.thar1.PVU-Paris.as6453.net(80.231.63.21)[AS6453] 0.523ms 0.522ms 0.516ms
  4 if-13-5.tcore1.PVU-Paris.as6453.net(80.231.153.177)[AS6453] 11.326 ms 11.310 ms 11.313 ms
  5 if-12-2.tcore1.PYE-Paris.as6453.net(80.231.154.69)[AS6453] 11.306 ms 11.555 ms 11.290 ms
  6 if-8-1600.tcore1.WYN-Marseille.as6453.net(80.231.217.5)[AS6453] 11.405 ms 11.362 ms if-14-2.tcore1.WYN-Marseille.as6453.net(80.231.154.170)[AS6453 ] 11.350毫秒
  7 if-2-2.tcore2.WYN-Marseille.as6453.net(80.231.217.2)[AS6453] 11.326 ms 11.428 ms 11.507 ms
  8 80.231.200.26(80.231.200.26)[AS6453] 105.722 ms 105.972 ms 107.541 ms
  9 * * *
 10 * * *
 11 * * *
 12 14.140.128.98.static-vsnl.net.in(14.140.128.98)[AS4755] 115.191ms 115.046ms 115.022ms
 13 ns2.r4ns.com(176.124.113.200)[as198412 / AS23033 / AS28513 / AS61163 / AS198412] 116.479 ms 114.806 ms 114.982 ms

或者从德国来到加州的洛杉矶:

跟踪路由到ns1.r4ns.com(176.124.112.100),最多16跳,40字节的数据包
  1 static.33.203.4.46.clients.your-server.de(46.4.203.33)[AS24940] 0.650 ms 3.633 ms 0.643 ms
  2 hos-tr4.juniper2.rz13.hetzner.de(213.239.224.97)[AS24940] 0.246 ms hos-tr3.juniper2.rz13.hetzner.de(213.239.224.65)[AS24940] 0.234 ms hos-tr2.juniper1.rz13 .hetzner.de(213.239.224.33)[AS24940] 0.236毫秒
  3 core21.hetzner.de(213.239.245.81)[AS24940] 1.203 ms core22.hetzner.de(213.239.245.121)[AS24940] 0.233 ms 0.236 ms
  4 core22.hetzner.de(213.239.245.162)[AS24940] 0.245 ms 0.236 ms core1.hetzner.de(213.239.245.177)[AS24940] 4.808 ms
  5 juniper1.ffm.hetzner.de(213.239.245.5)[AS24940] 4.837 ms core1.hetzner.de(213.239.245.177)[AS24940] 4.843 ms 4.825 ms
  6 dec-ix-c01.wvfiber.net(80.81.192.220)6.174 ms 6.230 ms juniper1.ffm.hetzner.de(213.239.245.5)[AS24940] 4.923 ms
  7 dec-ix-c01.wvfiber.net(80.81.192.220)6.223 ms ams-ten1-4-fra-ten2-1.bboi.net(66.216.50.57)[AS19151,AS19151] 29.457 ms 24.788 ms
  8 ams-ten1-4-fra-ten2-1.bboi.net(66.216.50.57)[AS19151,AS19151] 22.413 ms 19.756 ms ny60-vl2-ams-vl2.bboi.net(66.216.48.217)[AS19151] 109.138女士
  9 66.216.1.150(66.216.1.150)[AS19151] 127.527 ms ny60-vl2-ams-vl2.bboi.net(66.216.48.217)[AS19151] 109.68 ms 108.802 ms
 10 lv-ten1-3-chi-ten1-6.bboi.net(64.127.128.130)[AS19151] 171.983 ms 171.777 ms *
 11 lv-ten1-3-chi-ten1-6.bboi.net(64.127.128.130)[AS19151] 171.794 ms la-ten1-3-lv-ten1-3.bboi.net(66.186.192.21)[AS19151] 178.527毫秒177.967毫秒
 12 la-ten1-3-lv-ten1-3.bboi.net(66.186.192.21)[AS19151] 178.478ms 178.82ms 66.186.197.174(66.186.197.174)[AS19151] 178.281ms
 13 colo-lax6(96.44.180.102)[AS29761] 178.17 ms 66.186.197.174(66.186.197.174)[AS19151] 177.716 ms 177.935 ms
 14(lax-qn-gw.as36236.net)(72.11.150.122)[AS29761] 177.709 ms 177.764 ms colo-lax6(96.44.180.102)[AS29761] 184.72 ms
 15 lax-qn-gw.as36236.net(72.11.150.122)[AS29761] 178.34 ms 208.111.40.5(208.111.40.5)[AS36236] 175.688 ms 175.351 ms
 16 208.111.40.5(208.111.40.5)[AS36236] 175.641 ms 175.919 ms ns1.r4ns.com(176.124.112.100)[AS61163 198412] 176.590 ms

而从加利福尼亚州的圣何塞来到罗马尼亚,

跟踪路由到ns1.r4ns.com(176.124.112.100),最多16跳,60字节的数据包
  1 23.92.24.3(23.92.24.3)[*] 0.574 ms 0.704 ms 0.846 ms
  2 23.92.24.2(23.92.24.2)[*] 0.464 ms 0.589 ms 0.749 ms
  3 10gigabitethernet7-6.core3.fmt2.he.net(65.49.10.217)[AS6939] 0.256ms 0.263ms 0.245ms
  4 10gigabitethernet4-3.core1.dal1.he.net(72.52.92.154)[AS6939] 45.442ms 45.436ms 45.483ms
  5 10gigabitethernet5-4.core1.atl1.he.net(184.105.213.114)[AS6939] 65.805 ms 65.797 ms 65.757 ms
  6 10gigabitethernet16-5.core1.ash1.he.net(184.105.213.109)[AS6939] 74.565 ms 74.552 ms 74.537 ms
  7 10gigabitethernet9-2.core1.par2.he.net(184.105.213.94)[AS6939] 163.530 ms 163.534 ms 163.515 ms
  8 10gigabitethernet15-1.core1.fra1.he.net(72.52.92.25)[AS6939] 161.999ms 163.440ms 161.952ms
  9 * * 10Gbps.de-cix.adnettelecom.ro(80.81.194.100)[AS6695] 225.819 ms
 10 * * *
 11 cr.adnettelecom.ro(77.232.218.33)[AS5541] 193.016 ms 195.493 ms 250.588 ms
 12 10gbps.cr5.adnettelecom.ro(77.232.218.102)[AS5541] 249.048 ms 191.119 ms 192.532 ms
 13 ns1.r4ns.com(176.124.112.100)[as198412 / AS28513 / AS33597 / AS61163 / AS198412] 191.507 ms 246.698 ms 192.140 ms

为什么路由如此不理想? 是因为他们没有自己的骨干? 或者这种不良路由的解释是什么?