[Afpif] peer config to use root DNS anycast instances at an IXP

Dr P Nyirenda paulos at sdnp.org.mw
Fri Jan 1 12:11:33 UTC 2021


Happy new year 2021, am previledged to send you the first message on this AF-IX mailing 
list :-), hope we have good discussions in 2021

As the operator for the Malawi IXP (MIX), we have received a query from one or two ISPs on 
how to configure the ISP networks peering at the MIX so that they can use the anycast DNS 
root server instance at the MIX

With the help of PCH we operate d.root-servers.net and e.root-servers.net or D and E root 
DNS anycast instances at the MIX.

How should an ISP peering at the MIX configure its DNS to use the D and E root DNS 
instances at the MIX for it and its clients?

For example if I do a dig +trace like the one copied here below, you will see that my dig query 
was answered by c.root-servers.net which is at least 160ms away which is not the nearest 
DNS root server instance at the MIX

Our understanding is that the  nearest is d.root-server.net or e.root-servers.net as run by 
PCH which as you can see from the ping results also here below are around only 5ms away 
should have attended to or answered this query, but it did not.

So, why does this DNS dig query not use the nearby d.root-servers.net or the nearest 
e.root-server.net that PCH is running at the MIX?

How can we configure DNS at the ISPs or peers at the MIX to use the D or E root server 
instances as run by PCH at the MIX?

I have tried to send this query to PCH but so far there has been no answer. I hope you can 
help with a detailed answer.

Regards,

Paulos
=============================
Dr Paulos B Nyirenda
NIC.MW & .mw ccTLD 
http://www.nic.mw
SDNP: http://www.sdnp.org.mw
Tel:  +265-(0)-882 089 166
Cell: +265-(0)-888-824787
WhatsApp: +265-(0)-887386433



[paulos at domwe ~]$ dig +trace fred.nic.cz any

; <<>> DiG 9.9.3-rl.156.01-P1-RedHat-9.9.3-3.P1.fc17 <<>> +trace fred.nic.cz any
;; global options: +cmd
.                       517163  IN      NS      c.root-servers.net.
.                       517163  IN      NS      m.root-servers.net.
.                       517163  IN      NS      a.root-servers.net.
.                       517163  IN      NS      d.root-servers.net.
.                       517163  IN      NS      e.root-servers.net.
.                       517163  IN      NS      h.root-servers.net.
.                       517163  IN      NS      g.root-servers.net.
.                       517163  IN      NS      f.root-servers.net.
.                       517163  IN      NS      l.root-servers.net.
.                       517163  IN      NS      j.root-servers.net.
.                       517163  IN      NS      b.root-servers.net.
.                       517163  IN      NS      i.root-servers.net.
.                       517163  IN      NS      k.root-servers.net.
;; Received 811 bytes from 196.45.190.9#53(196.45.190.9) in 626 ms

cz.                     172800  IN      NS      d.ns.nic.cz.
cz.                     172800  IN      NS      b.ns.nic.cz.
cz.                     172800  IN      NS      a.ns.nic.cz.
cz.                     172800  IN      NS      c.ns.nic.cz.
cz.                     86400   IN      DS      20237 13 2 
CFF0F3ECDBC529C1F0031BA1840BFB835853B9209ED1E508FFF48451 D7B778E2
cz.                     86400   IN      RRSIG   DS 8 1 86400 20210103050000 20201221040000 
26116 . 0qIMZ74CtKJhxytWQd4Ox+ma4U5aUotYSWnBYDJB0bFxjK7uIL9RsILb 
+yk78V7t1cZjPxz0dLLSD781VuY5O7qif48rZov/TOo7eMooy4pHArZG 
cqEQq7saFAMfpHriTlzpR+Fhtec3fgTRnKBUbU7toWs7uGUcf09875a+ 
0WGsx8hM4ID6qMA8ADUtapvc3MHbsd3t4pYz+jA016pwdnkJiOEhlm2l 
YyQK7BPYDswAawFnYIHbdwVIaenYmsIo3zPkaQgQIzNNTQArmnK8kCI/ 
pA/ABMDtYqJEy/GYa8zP6IHmzOYWF7CN07x9kQipRDFB4RBY1MdXS9jL OqLRQw==
;; Received 618 bytes from 192.33.4.12#53(c.root-servers.net) in 796 ms

fred.nic.cz.            1800    IN      RRSIG   AAAA 13 3 1800 20210103182515 
20201220165515 44434 nic.cz. 
0Y8kKgQyzylIwq4foh4hkWrBuj9JgSmjsu2sawmKyp9kixPn+1B/yfpd 
rOkjWBYqBFUunM9lvMa/7J4D6uC66g==
fred.nic.cz.            1800    IN      AAAA    2001:1488:800:400::2:174
fred.nic.cz.            1800    IN      RRSIG   MX 13 3 1800 20210103182515 20201220165515 
44434 nic.cz. XzM7JC5pozXzq0xYoP75UOYRL9izlgaRerql70WY0NVle+rbbO53qneB 
15J2Arvssu03rLIahZcv1nvdsZvjng==
fred.nic.cz.            1800    IN      MX      10 mail.nic.cz.
fred.nic.cz.            1800    IN      RRSIG   A 13 3 1800 20210103182515 20201220165515 
44434 nic.cz. ZuTAZOfbeS62hZzf8k4zUFFrDtsN9X0hHDES3HHL9ay59ZOJOAFDt6dE 
awdoXUHmUKkAEfQIVw19/xPKERtf4g==
fred.nic.cz.            1800    IN      A       217.31.204.174
nic.cz.                 1800    IN      NS      b.ns.nic.cz.
nic.cz.                 1800    IN      NS      a.ns.nic.cz.
nic.cz.                 1800    IN      NS      d.ns.nic.cz.
nic.cz.                 1800    IN      RRSIG   NS 13 2 1800 20210103182515 20201220165515 
44434 nic.cz. ZMG1PaPmjqEKkSzmS7jlo6rv9zajhGuS0RqgJlLD7aIWDQz2viqWU6T/ 
K6ULCNgGJ9hwK2PDWnkhexct8JQ5LQ==
;; Received 1148 bytes from 193.29.206.1#53(d.ns.nic.cz) in 151 ms

[paulos at domwe ~]$
[paulos at domwe ~]$ ping d.root-servers.net
PING d.root-servers.net (199.7.91.13) 56(84) bytes of data.
64 bytes from d.root-servers.net (199.7.91.13): icmp_req=1 ttl=57 time=5.19 ms
64 bytes from d.root-servers.net (199.7.91.13): icmp_req=2 ttl=57 time=4.95 ms
64 bytes from d.root-servers.net (199.7.91.13): icmp_req=3 ttl=57 time=4.84 ms
^C
--- d.root-servers.net ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 4.840/4.995/5.190/0.166 ms
[paulos at domwe ~]$
[paulos at domwe ~]$
[paulos at domwe ~]$ ping e.root-servers.net
PING e.root-servers.net (192.203.230.10) 56(84) bytes of data.
64 bytes from e.root-servers.net (192.203.230.10): icmp_req=1 ttl=57 time=5.02 ms
64 bytes from e.root-servers.net (192.203.230.10): icmp_req=2 ttl=57 time=5.03 ms
64 bytes from e.root-servers.net (192.203.230.10): icmp_req=3 ttl=57 time=4.85 ms
64 bytes from e.root-servers.net (192.203.230.10): icmp_req=4 ttl=57 time=4.98 ms
^C
--- e.root-servers.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2998ms
rtt min/avg/max/mdev = 4.857/4.974/5.030/0.085 ms
[paulos at domwe ~]$
[paulos at domwe ~]$
[paulos at domwe ~]$ ping c.root-servers.net
PING c.root-servers.net (192.33.4.12) 56(84) bytes of data.
64 bytes from c.root-servers.net (192.33.4.12): icmp_req=1 ttl=50 time=164 ms
64 bytes from c.root-servers.net (192.33.4.12): icmp_req=2 ttl=50 time=164 ms
64 bytes from c.root-servers.net (192.33.4.12): icmp_req=3 ttl=50 time=164 ms
64 bytes from c.root-servers.net (192.33.4.12): icmp_req=4 ttl=50 time=164 ms
^C
--- c.root-servers.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2998ms
rtt min/avg/max/mdev = 164.428/164.555/164.754/0.512 ms
[paulos at domwe ~]$



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