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+nanog@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