ANYCAST DNS by SHAURYA RASTOGI Root DNS Its

ANYCAST & DNS by SHAURYA RASTOGI

Root DNS Its is the top most DNS in the DNS hierarchy. It contains entries of DNS nameservers all top level domains (TLD) i. e. com, . net, . org etc

Root DNS(contd) There are total 13 root nameservers from A to M C, F, I, J, K, L, M nameservers are replicated around the world and use anycast to provide service

Anycast What is Anycasting ? How is it different from Multicasting and Unicasting and Broadcasting ?

Unicast Broadcast Multicast Anycast

Anycasting in DNS The Root DNS which uses anycast as service medium has multiple copies running around the world. When a TLD DNS lookup is done, the request is delivered to the “nearest” Root DNS.

Anycast over BGP DNS Root: K 193. 0. 14. 129 AS 2 AS 1 193. 0. 14. 129 AS 1 AS 3 193. 0. 14. 129 AS 3 AS 2 AS 4 193. 0. 14. 129 AS 1

Benefits of Anycasting in DNS Use of anycasting allows replication of single root DNS nameserver at multiple locations around the world. It reduces the latency in case of DNS lookup from root DNS. Reduce impact of DOS attacks.

Letter IPv 4 address IPv 6 address Old name Operator Location A 198. 41. 0. 4 2001: 503: ba 3 e: : 2: 3 0 ns. internic. net Veri. Sign Dulles, Virginia, U. S. B 192. 228. 79. 201 2001: 478: 65: : 53 ns 1. isi. edu USC-ISI Marina Del Rey, California, U. S. C 192. 33. 4. 12 c. psi. net Cogent Communications distributed using anycast D 128. 8. 10. 90 terp. umd. edu University of Maryland College Park, Maryland, U. S. E 192. 203. 230. 10 ns. nasa. gov NASA Mountain View, California, U. S. F 192. 5. 5. 241 ns. isc. org ISC distributed using anycast G 192. 112. 36. 4 ns. nic. ddn. mil Defense Information Systems Agency Columbus, Ohio, U. S. H 128. 63. 2. 53 2001: 500: 1: : 803 f: 2 35 aos. arl. army. mil U. S. Army Research Lab Aberdeen Proving Ground, Maryland, U. S. I 192. 36. 148. 17 2001: 7 fe: : 53 (testing) nic. nordu. net Autonomica distributed using anycast J 192. 58. 128. 30 2001: 503: C 27: : 2: 30 Veri. Sign distributed using anycast K 193. 0. 14. 129 2001: 7 fd: : 1 RIPE NCC distributed using anycast L 199. 7. 83. 42 (since November 2007; was 198. 32. 64. 12) 2001: 500: 3: : 42 ICANN distributed using anycast M 202. 12. 27. 33 2001: dc 3: : 35 WIDE Project distributed using anycast 2001: 500: 2 f: : f