<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Because they are connected at different points in the network and as such see different network faults. The servers can all be working fine, it the connections between them that are not working. <br><br><div dir="ltr">-- <div>Mark Andrews</div></div><div dir="ltr"><br><blockquote type="cite">On 11 Feb 2021, at 04:54, sami's strat <sami.strat@gmail.com> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><div dir="ltr">Thank you all for responding. One final query about this. I'm seeing this issue on my production servers at work. Yet, when I run the same queries at home, I don't see those failed queries. I actually flushed DNS cache, cleared Linux O/S cache, and even bounced my personal DNS server trying to reproduce the issue. But I could not.<div><br></div><div>TIA</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Feb 10, 2021 at 12:09 AM Mark Andrews <<a href="mailto:marka@isc.org">marka@isc.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Run ‘dig +trace +all <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>’ which will show you the glue<br>
records then try ‘dig +dnssec +norec <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a> @<address>’ for<br>
all the addresses in the glue records.<br>
<br>
e.g.<br>
dig +dnssec +norec <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a> @<a href="http://146.243.122.17" rel="noreferrer" target="_blank">146.243.122.17</a><br>
<br>
Mark<br>
<br>
> On 10 Feb 2021, at 14:50, sami's strat <<a href="mailto:sami.strat@gmail.com" target="_blank">sami.strat@gmail.com</a>> wrote:<br>
> <br>
> Thanks Mark.<br>
> <br>
> However, the traceroute to the hostnamed failed for the same reason. Please note:<br>
> <br>
> [root@myhost data]# dig <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a><br>
> <br>
> ; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a><br>
> ;; global options: +cmd<br>
> ;; Got answer:<br>
> ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 61641<br>
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1<br>
> <br>
> ;; OPT PSEUDOSECTION:<br>
> ; EDNS: version: 0, flags:; udp: 4096<br>
> ;; QUESTION SECTION:<br>
> ;<a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>. IN A<br>
> <br>
> ;; Query time: 1263 msec<br>
> ;; SERVER: 192.168.33.12#53(192.168.33.12)<br>
> ;; WHEN: Tue Feb 09 22:34:15 EST 2021<br>
> ;; MSG SIZE rcvd: 54<br>
> <br>
> [root@myhost data]# dig <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a> +trace<br>
> <br>
> ; <<>> DiG 9.11.4-P2-RedHat-9.11.4-9.P2.el7 <<>> <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a> +trace<br>
> ;; global options: +cmd<br>
> . 516485 IN NS <a href="http://c.root-servers.net" rel="noreferrer" target="_blank">c.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://e.root-servers.net" rel="noreferrer" target="_blank">e.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://f.root-servers.net" rel="noreferrer" target="_blank">f.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://l.root-servers.net" rel="noreferrer" target="_blank">l.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://m.root-servers.net" rel="noreferrer" target="_blank">m.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://d.root-servers.net" rel="noreferrer" target="_blank">d.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://g.root-servers.net" rel="noreferrer" target="_blank">g.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://k.root-servers.net" rel="noreferrer" target="_blank">k.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://b.root-servers.net" rel="noreferrer" target="_blank">b.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://h.root-servers.net" rel="noreferrer" target="_blank">h.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://a.root-servers.net" rel="noreferrer" target="_blank">a.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://i.root-servers.net" rel="noreferrer" target="_blank">i.root-servers.net</a>.<br>
> . 516485 IN NS <a href="http://j.root-servers.net" rel="noreferrer" target="_blank">j.root-servers.net</a>.<br>
> . 516485 IN RRSIG NS 8 0 518400 20210222230000 20210209220000 42351 . QCzDH8eHlHVbx4SxIIwk8xnk6ky/q+zRh8KAUfI98lqHcIP4NLxzCe6f mC2sNX1VcthEy6Lwnobm8OyJCRpNEHedYrS01aMhAVzUfM+/PJ9MWn0w SkmXxyZMJZXF/kl4GDNX0x/GW3+DkeTeZI9+B540Yvj47qJv2bD9nIQG NtE7bDze7bgMJkIuBlEzPfwp7YW5ud8qdC6HdUoEMqygwZcWAiQu8gpb q21z8W5hcdci1OouDFytNWrXAvfSsuR635+GzSj+RZjYo+447uP7lKsK N5aeVQ/BPh5jM32xVO+zwyp7v9Nky1vSP/BchMQ/3cqg3Ee7zobl8OQd CSd/SA==<br>
> ;; Received 1097 bytes from 192.168.33.12#53(192.168.33.12) in 0 ms<br>
> <br>
> us. 172800 IN NS <a href="http://a.cctld.us" rel="noreferrer" target="_blank">a.cctld.us</a>.<br>
> us. 172800 IN NS <a href="http://b.cctld.us" rel="noreferrer" target="_blank">b.cctld.us</a>.<br>
> us. 172800 IN NS <a href="http://c.cctld.us" rel="noreferrer" target="_blank">c.cctld.us</a>.<br>
> us. 172800 IN NS <a href="http://e.cctld.us" rel="noreferrer" target="_blank">e.cctld.us</a>.<br>
> us. 172800 IN NS <a href="http://f.cctld.us" rel="noreferrer" target="_blank">f.cctld.us</a>.<br>
> us. 172800 IN NS <a href="http://k.cctld.us" rel="noreferrer" target="_blank">k.cctld.us</a>.<br>
> us. 86400 IN DS 21364 8 1 260D0461242BCF8F05473A08B05ED01E6FA59B9C<br>
> us. 86400 IN DS 21364 8 2 B499CFA7B54D25FDE1E6FE93076FB013DAA664DA1F26585324740A1E 6EBDAB26<br>
> us. 86400 IN RRSIG DS 8 1 86400 20210222230000 20210209220000 42351 . rujvGB0s2bsqzBuzRliH6QK9vH84ETZV7gZMEhJyzMFofWhj9ZZaNWE/ VvdA9rC16IOEocvARv2rOqk7G3KTzdkHHZcwcZSQyVqsOIaIywGFuEgd viSXF6+M5MocUgEMp5dtt6SBLHG+lE/FV/3HylKSHsxdO/F6PeWKgcBZ D4lZQ6w5asmlbdKJKMhlWPp6UaxBE7ACaxndBQixoNqXQuPrXpXi1Fnj ntFtTfn57hMyrdTojIJ8X7/HKjCrbm3CL/WJ+VZR051OGCdZVjpUaDXR x7G9lDhu3K5clar9PGYyUJM7+RBKzrQJep7HrjL2nZdoTyfY4i33S+EZ sTlTOA==<br>
> ;; Received 707 bytes from 199.7.91.13#53(<a href="http://d.root-servers.net" rel="noreferrer" target="_blank">d.root-servers.net</a>) in 4 ms<br>
> <br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 7200 IN NS <a href="http://internet-dns3.state.ma.us" rel="noreferrer" target="_blank">internet-dns3.state.ma.us</a>.<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 7200 IN NS <a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>.<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 7200 IN NS <a href="http://internet-dns2.state.ma.us" rel="noreferrer" target="_blank">internet-dns2.state.ma.us</a>.<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 3600 IN DS 47628 7 2 5379F9F747214E5A63416775396BCFF98FA4867AE66E09BCBEBE0DCC 1682C369<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 3600 IN DS 41388 7 1 36D899932AF794EADD671161515E48FE829BB7FE<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 3600 IN DS 41388 7 2 BBAB433D3853571F42516E70659AF1F85FA4FBA0FDFCEAD4D092592A 00C78769<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 3600 IN DS 47628 7 1 485E0EE2F7C08FCE51D1E284321242930274833A<br>
> <a href="http://state.ma.us" rel="noreferrer" target="_blank">state.ma.us</a>. 3600 IN RRSIG DS 8 3 3600 20210307200856 20210205191212 53985 us. O8KqBHzlZsDqrZi0NQO4JEiN0b8j04/Lb8W2uVz5PyrAat1VgZKQ3Ws6 6PNtbZDMv6YX6QA8fWFLxNmeJ1/4L3wLu8EKYXaThA9Zxll7mKFj1iPf nqiVq5hOo8Ul3inmfM/tjCQ21IHc/v0JZygZNd/h0SxXWlQXi+W3G9LN +4z/qxtl9dGD1ka54Ln3MAVxB1Tp4pt0ri4qPLmfGKf/HA==<br>
> couldn't get address for '<a href="http://internet-dns3.state.ma.us" rel="noreferrer" target="_blank">internet-dns3.state.ma.us</a>': not found<br>
> couldn't get address for '<a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>': not found<br>
> couldn't get address for '<a href="http://internet-dns2.state.ma.us" rel="noreferrer" target="_blank">internet-dns2.state.ma.us</a>': not found<br>
> dig: couldn't get address for '<a href="http://internet-dns3.state.ma.us" rel="noreferrer" target="_blank">internet-dns3.state.ma.us</a>': no more<br>
> [root@myhost data]#<br>
> <br>
> On Tue, Feb 9, 2021 at 10:10 PM Mark Andrews <<a href="mailto:marka@isc.org" target="_blank">marka@isc.org</a>> wrote:<br>
> Well you could try tracing the addresses of the nameservers for which<br>
> there where errors reported. It could be as simple as a routing issue<br>
> between you and these servers.<br>
> <br>
> > On 10 Feb 2021, at 13:25, sami's strat <<a href="mailto:sami.strat@gmail.com" target="_blank">sami.strat@gmail.com</a>> wrote:<br>
> > <br>
> > couldn't get address for '<a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>': not found<br>
> > couldn't get address for '<a href="http://internet-dns3.state.ma.us" rel="noreferrer" target="_blank">internet-dns3.state.ma.us</a>': not found<br>
> > couldn't get address for '<a href="http://internet-dns2.state.ma.us" rel="noreferrer" target="_blank">internet-dns2.state.ma.us</a>': not found<br>
> > dig: couldn't get address for '<a href="http://internet-dns1.state.ma.us" rel="noreferrer" target="_blank">internet-dns1.state.ma.us</a>': no more<br>
> <br>
> Yet, I do this on my personal computer at home, and it works without an issue.<br>
> <br>
> Any other thoughts? TIA <br>
<br>
-- <br>
Mark Andrews, ISC<br>
1 Seymour St., Dundas Valley, NSW 2117, Australia<br>
PHONE: +61 2 9871 4742 INTERNET: <a href="mailto:marka@isc.org" target="_blank">marka@isc.org</a><br>
<br>
</blockquote></div>
</div></blockquote></body></html>