NTTのバックボーン設備障害で海外のサイトが見えないというトラブルがあったが、twitterを見てると「DNSをGoogle Public DNSにすると見える」という話があがっていたのでちょっと考えていた。
というのも、バックボーン設備障害だとDNSだけじゃなくて、そこを経由している全通信がアウトになるはず。
そこでtracerouteを打ってみた。
まずは先にDNS鯖。
twitterのDNS鯖
% dig NS twitter.com.
;; ANSWER SECTION:
twitter.com. 84910 IN NS ns3.p34.dynect.net.
twitter.com. 84910 IN NS ns4.p34.dynect.net.
twitter.com. 84910 IN NS ns1.p34.dynect.net.
twitter.com. 84910 IN NS ns2.p34.dynect.net.
;; ADDITIONAL SECTION:
ns1.p34.dynect.net. 84910 IN A 208.78.70.34
ns2.p34.dynect.net. 84910 IN A 204.13.250.34
ns3.p34.dynect.net. 84910 IN A 208.78.71.34
ns4.p34.dynect.net. 84910 IN A 204.13.251.34
ns1.p34.dynect.net.(208.78.70.34)にtracerouteを打ってみる。
★eo光
% traceroute 208.78.70.34
traceroute to 208.78.70.34 (208.78.70.34), 64 hops max, 40 byte packets
1 opt90 (192.168.1.254) 0.651 ms 0.387 ms 0.353 ms
2 60.56.25.68 (60.56.25.68) 3.717 ms 2.506 ms 1.718 ms
3 60.56.26.153 (60.56.26.153) 1.402 ms 1.445 ms 2.161 ms
4 121.83.231.233 (121.83.231.233) 1.572 ms 1.390 ms 1.934 ms
5 219.122.245.137 (219.122.245.137) 1.801 ms 1.491 ms 1.793 ms
6 61.200.82.33 (61.200.82.33) 2.189 ms 1.759 ms 2.320 ms
7 xe-3-3.a15.tokyjp01.jp.ra.gin.ntt.net (61.213.162.205) 10.392 ms 9.047 ms 9.025 ms
8 ae-9.r24.tokyjp01.jp.bb.gin.ntt.net (203.105.72.153) 9.311 ms
ae-9.r25.tokyjp01.jp.bb.gin.ntt.net (203.105.72.157) 67.066 ms
ae-9.r24.tokyjp01.jp.bb.gin.ntt.net (203.105.72.153) 8.923 ms
9 xe-1-0-0.r20.tokyjp03.jp.bb.gin.ntt.net (129.250.3.129) 11.837 ms 11.517 ms
xe-0-0-0.r20.tokyjp03.jp.bb.gin.ntt.net (129.250.3.25) 11.644 ms
10 ge-1-1-8.r20.tokyjp03.jp.ce.gin.ntt.net (61.120.145.174) 10.442 ms 10.813 ms 9.748 ms
11 ge-1-1-8.r20.tokyjp03.jp.ce.gin.ntt.net (61.120.145.174) 10.950 ms !X 9.980 ms !X 10.610 ms !X
さくらインターネット鯖
% traceroute 208.78.70.34
traceroute to 208.78.70.34 (208.78.70.34), 64 hops max, 40 byte packets
1 219.94.162.129 (219.94.162.129) 4.311 ms 1.913 ms 1.480 ms
2 osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 0.971 ms
osnrt102b-nrt107e.bb.sakura.ad.jp (59.106.253.185) 2.944 ms
osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 2.450 ms
3 osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 1.439 ms
osnrt1s-nrt101b.bb.sakura.ad.jp (59.106.244.137) 1.464 ms
osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 1.453 ms
4 osdrt1-nrt1s-1.bb.sakura.ad.jp (59.106.255.1) 3.447 ms
osdrt1-nrt1s-2.bb.sakura.ad.jp (59.106.255.5) 0.956 ms 0.448 ms
5 ge-0-0-0.a01.osakjp01.jp.ra.gin.ntt.net (61.200.82.21) 0.974 ms 0.954 ms 0.981 ms
6 xe-9-3.a14.tokyjp01.jp.ra.gin.ntt.net (61.213.162.201) 7.971 ms 11.950 ms 8.477 ms
7 ae-8.r25.tokyjp01.jp.bb.gin.ntt.net (203.105.72.149) 9.969 ms
ae-8.r24.tokyjp01.jp.bb.gin.ntt.net (61.213.160.241) 10.446 ms
ae-8.r25.tokyjp01.jp.bb.gin.ntt.net (203.105.72.149) 8.446 ms
8 xe-0-0-0.r20.tokyjp03.jp.bb.gin.ntt.net (129.250.3.25) 12.940 ms
xe-1-0-0.r20.tokyjp03.jp.bb.gin.ntt.net (129.250.3.129) 13.434 ms
xe-0-0-0.r20.tokyjp03.jp.bb.gin.ntt.net (129.250.3.25) 12.947 ms
9 ge-1-1-8.r20.tokyjp03.jp.ce.gin.ntt.net (61.120.145.174) 12.441 ms 13.941 ms 11.974 ms
10 ge-1-1-8.r20.tokyjp03.jp.ce.gin.ntt.net (61.120.145.174) 9.470 ms !X 9.943 ms !X 9.474 ms !X
次にtwitterのWeb鯖にtracerouteを打ってみる。
% dig twitter.com.
;; ANSWER SECTION:
twitter.com. 30 IN A 199.59.148.10
twitter.com. 30 IN A 199.59.149.198
twitter.com. 30 IN A 199.59.149.230
★eo光
% traceroute 199.59.149.198
traceroute to 199.59.149.198 (199.59.149.198), 64 hops max, 40 byte packets
1 opt90 (192.168.1.254) 25.236 ms 78.797 ms 0.280 ms
2 60.56.25.68 (60.56.25.68) 6.116 ms 25.860 ms 14.655 ms
3 60.56.26.153 (60.56.26.153) 1.240 ms 1.582 ms 2.113 ms
4 121.83.231.233 (121.83.231.233) 1.280 ms 1.568 ms 2.042 ms
5 219.122.245.73 (219.122.245.73) 1.943 ms 2.071 ms 2.128 ms
6 202.232.11.93 (202.232.11.93) 4.172 ms 1.901 ms 2.020 ms
7 osk005bb10.IIJ.Net (58.138.111.201) 1.557 ms
osk005bb11.IIJ.Net (58.138.111.213) 1.726 ms
osk005bb10.IIJ.Net (58.138.111.201) 2.032 ms
8 osk004bf01.IIJ.Net (58.138.81.33) 2.071 ms
osk004bf01.IIJ.Net (58.138.81.37) 2.058 ms
osk004bf00.IIJ.Net (58.138.81.25) 2.142 ms
9 lax002bf02.IIJ.Net (206.132.169.113) 124.508 ms
lax002bf00.IIJ.net (206.132.169.117) 108.796 ms
lax002bf02.IIJ.Net (206.132.169.113) 124.512 ms
10 sjc002bb10.IIJ.net (206.132.169.90) 126.082 ms 171.877 ms
sjc002bb10.IIJ.net (206.132.169.94) 128.842 ms
11 eqix1.cr1.sjc2.twttr.com (206.223.116.94) 130.060 ms
eqix2.cr2.sjc2.twttr.com (206.223.116.101) 119.989 ms 126.898 ms
12 xe-11-0-0.smf1-er1.twttr.com (199.16.159.51) 134.072 ms
xe-0-0-0.smf1-er1.twttr.com (199.16.159.37) 134.558 ms
xe-10-0-0.smf1-er2.twttr.com (199.16.159.53) 133.368 ms
13 www2.twitter.com (199.59.149.198) 135.117 ms 139.535 ms 142.858 ms
★さくらインターネット鯖
traceroute 199.59.149.198
traceroute to 199.59.149.198 (199.59.149.198), 64 hops max, 40 byte packets
1 219.94.162.129 (219.94.162.129) 1.406 ms 1.916 ms 0.480 ms
2 osnrt102b-nrt107e.bb.sakura.ad.jp (59.106.253.185) 0.971 ms
osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 1.943 ms
osnrt102b-nrt107e.bb.sakura.ad.jp (59.106.253.185) 0.943 ms
3 osdrt1-nrt101b.bb.sakura.ad.jp (59.106.255.37) 0.948 ms
osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 2.453 ms
osdrt1-nrt101b.bb.sakura.ad.jp (59.106.255.37) 0.953 ms
4 oskrt1-nrt1s.bb.sakura.ad.jp (59.106.255.17) 0.947 ms
oskrt1-drt1.bb.sakura.ad.jp (59.106.255.82) 0.935 ms
oskrt1-nrt1s.bb.sakura.ad.jp (59.106.255.17) 2.457 ms
5 124.211.15.21 (124.211.15.21) 1.436 ms 11.953 ms 1.480 ms
6 obpjbb204.kddnet.ad.jp (118.155.199.65) 2.975 ms
obpjbb204.kddnet.ad.jp (118.155.199.69) 4.964 ms
obpjbb203.kddnet.ad.jp (118.155.199.21) 1.454 ms
7 pajbb001.kddnet.ad.jp (203.181.100.142) 117.401 ms 145.872 ms
pajbb002.kddnet.ad.jp (203.181.100.214) 104.918 ms
8 ix-pa8.kddnet.ad.jp (111.87.3.30) 120.862 ms 109.399 ms
ix-pa8.kddnet.ad.jp (111.87.3.6) 122.397 ms
9 ge-2-0-2.pao1-cr2.twttr.com (199.16.159.185) 112.372 ms 110.390 ms 102.429 ms
10 xe-11-0-0.smf1-er2.twttr.com (199.16.159.55) 105.908 ms 109.892 ms
xe-1-0-0.smf1-er1.twttr.com (199.16.159.29) 121.412 ms
11 www2.twitter.com (199.59.149.198) 116.376 ms 114.919 ms 106.904 ms
次にfacebook。
% dig NS facebook.com.
;; ANSWER SECTION:
facebook.com. 170854 IN NS ns2.facebook.com.
facebook.com. 170854 IN NS ns5.facebook.com.
facebook.com. 170854 IN NS ns3.facebook.com.
facebook.com. 170854 IN NS ns1.facebook.com.
facebook.com. 170854 IN NS ns4.facebook.com.
;; ADDITIONAL SECTION:
ns1.facebook.com. 3585 IN A 204.74.66.132
ns2.facebook.com. 3594 IN A 204.74.67.132
ns3.facebook.com. 3596 IN A 66.220.151.20
ns4.facebook.com. 3598 IN A 69.63.186.49
ns5.facebook.com. 3566 IN A 66.220.145.65
facebookのDNSにtracerouteを。
★eo光
% traceroute 204.74.66.132
traceroute 204.74.66.132
traceroute to 204.74.66.132 (204.74.66.132), 64 hops max, 40 byte packets
1 opt90 (192.168.1.254) 0.298 ms 0.248 ms 0.238 ms
2 60.56.25.68 (60.56.25.68) 3.033 ms 3.537 ms 2.137 ms
3 60.56.26.157 (60.56.26.157) 1.741 ms 1.840 ms 2.061 ms
4 121.83.231.241 (121.83.231.241) 1.260 ms 1.386 ms 2.106 ms
5 219.122.245.73 (219.122.245.73) 1.272 ms 1.764 ms 2.134 ms
6 202.232.11.93 (202.232.11.93) 1.457 ms 1.703 ms 1.487 ms
7 osk005bb10.IIJ.Net (58.138.111.201) 2.237 ms
osk005bb11.IIJ.Net (58.138.111.205) 1.427 ms
osk005bb10.IIJ.Net (58.138.111.201) 2.044 ms
8 osk004bf00.IIJ.Net (58.138.81.29) 2.638 ms
osk004bf00.IIJ.Net (58.138.81.25) 2.660 ms 1.864 ms
9 lax002bf00.IIJ.net (206.132.169.117) 106.497 ms
lax002bb10.IIJ.net (216.98.96.65) 106.104 ms
lax002bf02.IIJ.Net (206.132.169.113) 125.255 ms
10 sjc002bb10.IIJ.net (206.132.169.98) 133.495 ms
sjc002bb10.IIJ.net (206.132.169.90) 126.782 ms
sjc002bb10.IIJ.net (206.132.169.94) 128.564 ms
11 sjc002bb01.IIJ.net (216.98.96.109) 128.690 ms 124.284 ms 121.246 ms
12 nyc002bb01.IIJ.net (216.98.96.154) 206.734 ms 204.660 ms 211.422 ms
13 nyc002bb00.IIJ.net (206.132.169.101) 211.942 ms 211.975 ms 211.769 ms
14 rtrpxny.ultradns.net (198.32.118.61) 205.113 ms 212.511 ms 212.577 ms
15 * * ^C
※待つのめんどくせーから途中で中止
★さくらインターネット鯖
% traceroute 204.74.66.132
traceroute to 204.74.66.132 (204.74.66.132), 64 hops max, 40 byte packets
1 219.94.162.129 (219.94.162.129) 3.628 ms 1.412 ms 4.479 ms
2 osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 5.965 ms
osnrt102b-nrt107e.bb.sakura.ad.jp (59.106.253.185) 4.442 ms
osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 3.480 ms
3 osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 1.448 ms
osnrt1s-nrt101b.bb.sakura.ad.jp (59.106.244.137) 4.441 ms
osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 4.425 ms
4 osdrt2-nrt1s-2.bb.sakura.ad.jp (59.106.255.13) 3.923 ms 4.449 ms
osdrt2-nrt1s-1.bb.sakura.ad.jp (59.106.255.9) 11.476 ms
5 210.130.146.193 (210.130.146.193) 4.946 ms 7.952 ms 1.476 ms
6 osk004bb01.IIJ.Net (58.138.106.181) 1.476 ms 4.452 ms 4.480 ms
7 osk004bf00.IIJ.Net (58.138.81.145) 4.472 ms
osk004bf01.IIJ.Net (58.138.81.113) 23.971 ms 4.414 ms
8 lax002bf01.IIJ.net (216.98.96.190) 117.937 ms 115.872 ms 117.945 ms
9 sjc002bb10.IIJ.net (206.132.169.90) 129.380 ms 125.348 ms 128.394 ms
^C
※待つのめんどくせーから途中で中止
facebookのWeb鯖にtracerouteを打ってみる。
% dig facebook.com.
;; ANSWER SECTION:
facebook.com. 2606 IN A 69.171.224.11
facebook.com. 2606 IN A 69.171.229.11
facebook.com. 2606 IN A 66.220.149.11
★eo光
% traceroute 69.171.224.11
traceroute 69.171.224.11
traceroute to 69.171.224.11 (69.171.224.11), 64 hops max, 40 byte packets
1 opt90 (192.168.1.254) 0.300 ms 0.275 ms 0.217 ms
2 60.56.25.68 (60.56.25.68) 4.061 ms 1.979 ms 2.192 ms
3 60.56.26.9 (60.56.26.9) 1.780 ms 1.285 ms 1.478 ms
4 121.83.231.233 (121.83.231.233) 1.139 ms 1.647 ms 1.169 ms
5 219.122.245.137 (219.122.245.137) 1.481 ms 1.367 ms 1.151 ms
6 KOC-0004.gw3.osa1.asianetcom.net (203.192.150.1) 14.161 ms 13.846 ms 14.016 ms
7 te0-2-1-0.wr1.osa0.asianetcom.net (61.14.157.145) 14.521 ms 14.172 ms 14.081 ms
8 gi6-0-0.gw1.sjc1.asianetcom.net (61.14.157.98) 115.513 ms 115.787 ms 115.755 ms
9 * * *
10 ae0.bb01.sjc1.tfbnw.net (74.119.76.21) 126.219 ms
ae1.bb02.sjc1.tfbnw.net (204.15.21.164) 120.052 ms
ae0.bb01.sjc1.tfbnw.net (74.119.76.21) 126.385 ms
^C
※待つのめんどくせーから途中で中止
★さくらインターネット鯖
% traceroute 69.171.224.11
traceroute to 69.171.224.11 (69.171.224.11), 64 hops max, 40 byte packets
1 219.94.162.129 (219.94.162.129) 0.812 ms 3.414 ms 0.478 ms
2 osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 1.496 ms
osnrt102b-nrt107e.bb.sakura.ad.jp (59.106.253.185) 0.481 ms
osnrt101b-nrt107e.bb.sakura.ad.jp (59.106.253.81) 4.447 ms
3 osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 0.436 ms
osnrt1s-nrt101b.bb.sakura.ad.jp (59.106.244.137) 0.453 ms
osnrt1s-nrt102b.bb.sakura.ad.jp (59.106.244.141) 3.421 ms
4 osdrt1-nrt1s-1.bb.sakura.ad.jp (59.106.255.1) 3.486 ms
osdrt1-nrt1s-2.bb.sakura.ad.jp (59.106.255.5) 3.945 ms 0.455 ms
5 ge-0-0-0.a01.osakjp01.jp.ra.gin.ntt.net (61.200.82.21) 0.982 ms 5.942 ms 0.480 ms
6 xe-9-3.a14.tokyjp01.jp.ra.gin.ntt.net (61.213.162.201) 106.927 ms 116.378 ms 24.464 ms
7 ae-8.r25.tokyjp01.jp.bb.gin.ntt.net (203.105.72.149) 9.970 ms
ae-8.r24.tokyjp01.jp.bb.gin.ntt.net (61.213.160.241) 112.393 ms
ae-8.r25.tokyjp01.jp.bb.gin.ntt.net (203.105.72.149) 10.939 ms
8 ae-1.r20.tokyjp01.jp.bb.gin.ntt.net (129.250.2.20) 11.940 ms
ae-9.r20.tokyjp01.jp.bb.gin.ntt.net (129.250.2.92) 9.946 ms
ae-1.r20.tokyjp01.jp.bb.gin.ntt.net (129.250.2.20) 14.445 ms
9 as-1.r20.sttlwa01.us.bb.gin.ntt.net (129.250.4.189) 100.436 ms 109.885 ms 100.424 ms
10 ae-1.r04.sttlwa01.us.bb.gin.ntt.net (129.250.5.43) 107.431 ms 105.865 ms 114.917 ms
11 198.104.202.2 (198.104.202.2) 109.412 ms 93.893 ms 92.928 ms
12 BE1.bb03.sea1.tfbnw.net (31.13.24.57) 122.909 ms 127.884 ms 106.912 ms
13 ae9.bb01.sea1.tfbnw.net (31.13.24.60) 127.902 ms 151.342 ms 128.365 ms
^C
※待つのめんどくせーから途中で中止
今回の場合、仮にさくらインターネット鯖のDNSをGoogle Public DNSに変更できても
- twitter.comの名前解決を行うDNSは経路が変わり、twitterのWeb鯖まではNTTの足を経由しないので問題は解決する。
- facebook.comの名前解決を行うDNSまではNTTの足を使わないので問題ないが、facebookのWeb鯖に到達するまでにNTTの足を通るので結果的に問題は解決しない。
となり、つまり「Google Public DNSを使うと問題は解決する」というのは「必ずしも正解ではない」ということか。
実際、障害中にそうなったかどうかがわからないのでなんとも言えないが。
└ G兄
└ G兄
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└ 山銀
└ G兄