I'm getting similar results on residential Comcast up here in Michigan, US (Comcast's Heartland region). Checking from a Google Cloud vm in Iowa, US, I was able to reach m.root-servers.net via both v4 and v6, but it looks like it's routing to the Sao Paulo cluster in both cases (looking at https://m.root-servers.org/, I would have assumed it would have routed to SF's cluster)
test-instance-3:~$ ping m.root-servers.net PING m.root-servers.net(M.ROOT-SERVERS.NET (2001:dc3::35)) 56 data bytes 64 bytes from M.ROOT-SERVERS.NET (2001:dc3::35): icmp_seq=1 ttl=63 time=141 ms 64 bytes from M.ROOT-SERVERS.NET (2001:dc3::35): icmp_seq=2 ttl=63 time=141 ms 64 bytes from M.ROOT-SERVERS.NET (2001:dc3::35): icmp_seq=3 ttl=63 time=141 ms ^C --- m.root-servers.net ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 140.752/140.903/141.091/0.140 ms test-instance-3:~$ dig +short m.root-servers.net 202.12.27.33 test-instance-3:~$ ping 202.12.27.33 PING 202.12.27.33 (202.12.27.33) 56(84) bytes of data. 64 bytes from 202.12.27.33: icmp_seq=1 ttl=254 time=143 ms 64 bytes from 202.12.27.33: icmp_seq=2 ttl=254 time=140 ms 64 bytes from 202.12.27.33: icmp_seq=3 ttl=254 time=141 ms ^C --- 202.12.27.33 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2003ms rtt min/avg/max/mdev = 140.387/141.368/143.146/1.259 ms test-instance-3:~$ traceroute -I m.root-servers.net traceroute to m.root-servers.net (202.12.27.33), 64 hops max 1 * * * 2 142.251.64.24 140.646ms 140.640ms 140.749ms 3 187.16.215.148 140.371ms 140.292ms 140.314ms 4 202.12.27.33 139.841ms 140.324ms 139.980ms test-instance-3:~$ dig -x 187.16.215.148 ... 148.215.16.187.in-addr.arpa. 6423 IN PTR as7500.saopaulo.sp.ix.br. ... test-instance-3:~$ traceroute6 m.root-servers.net traceroute to m.root-servers.net (2001:dc3::35) from 2600:1900:4000:d977:0:1::, 30 hops max, 24 byte packets 1 * * * 2 2001:4860:0:1::7cd8 (2001:4860:0:1::7cd8) 140.1891 ms 140.0114 ms 140.0064 ms 3 as7500.saopaulo.sp.ix.br (2001:12f8::215:148) 140.7670 ms 140.7445 ms 140.7408 ms 4 M.ROOT-SERVERS.NET (2001:dc3::35) 140.5523 ms 140.4191 ms 140.4163 ms On Sun, Aug 25, 2024 at 8:18 PM Crist Clark <cjc+na...@pumpky.net> wrote: > Debated whether to bring this up on the OARC DNS Ops list or NANOG. Seem > more of a network-y thing. > > I happened to notice that I cannot query or ping m.root-servers.net's IPv4 > address from my home Comcast connection (SF Bay Area). IPv6 works. All of > the other root servers are reachable via both IPv4 and IPv6. > > Just me or all Comcast users? > > Obviously, nothing critical. My DNS servers will work just fine with one > root unavailable on one protocol. But curious what's broken. Been this way > for at least a couple of weeks. > > Compare IPv4 and IPv6 traceroutes, > > Mac-Air:~ fred$ traceroute -I m.root-servers.net > > traceroute to m.root-servers.net (202.12.27.33), 64 hops max, 72 byte > packets > > 1 moat (192.168.64.90) 3.004 ms 1.409 ms 1.155 ms > > 2 10.60.234.131 (10.60.234.131) 14.354 ms 17.153 ms 14.451 ms > > 3 po-313-1222-rur202.pleasanton.ca.sfba.comcast.net (96.110.179.157) 14.296 > ms 11.150 ms 11.279 ms > > 4 po-200-xar02.pleasanton.ca.sfba.comcast.net (68.85.155.117) 11.752 ms > 10.195 ms 11.783 ms > > 5 be-248-rar01.pleasanton.ca.sfba.comcast.net (96.108.99.129) 14.261 ms > 11.228 ms 13.187 ms > > 6 be-398-ar01.hayward.ca.sfba.comcast.net (162.151.87.225) 13.577 ms > 13.552 > ms 13.725 ms > > 7 * * * > > 8 * * * > > 9 * * * > > 10 * * * > > 11 * * * > > 12 *^C > > Mac-Air:~ fred$ traceroute6 -I m.root-servers.net > > traceroute6 to m.root-servers.net (2001:dc3::35) from > 2601:644:8f01:3b0:c842:51d6:e589:5203, 64 hops max, 16 byte packets > > 1 2601:644:8f01:3b0:4262:31ff:fe01:b8 1.753 ms 1.765 ms 1.343 ms > > 2 2001:558:101e:54::2 14.526 ms 26.113 ms 32.365 ms > > 3 po-313-1221-rur201.pleasanton.ca.sfba.comcast.net 28.170 ms 14.109 > ms 11.374 ms > > 4 po-200-xar01.pleasanton.ca.sfba.comcast.net 11.746 ms 20.031 ms 42.526 > ms > > 5 * * * > > 6 * * * > > 7 * * * > > 8 lo-0-v6.ear2.sanjose1.level3.net 15.106 ms 14.454 ms 13.240 ms > > 9 pt.telekomu.edge1.losangeles9.level3.net 15.921 ms 17.188 ms 16.294 > ms > > 10 m.root-servers.net 17.032 ms 15.169 ms 14.892 ms > > >
