On Nov 11, 2011, at 1:38 PM, Gaurav Kansal wrote: > Dear All, > > Somewhere I read that number of ROOT DNS servers is limited to 13 because of > protocol limitation of DNS and UDP. > Exact writing was “A combination of limits in the DNS and certain protocols, > namely the practical size of unfragmented User Datagram Protocol (UDP) > packets, resulted in a limited number of root server addresses that can be > accommodated in DNS name query responses. This limit has determined the > number of name server installations at (currently) 13 clusters, serving the > needs of the entire public Internet worldwide.” > > As root DNS are running in anycast so number is not an issue at all.
Yes, but you still need the names ([a-m].root-servers.net) and the (anycasted) addresses for each... dig NS @a.root-servers.net ; <<>> DiG 9.6.-ESV-R3 <<>> NS @a.root-servers.net ; (2 servers found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 45020 ;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 518400 IN NS b.root-servers.net. . 518400 IN NS g.root-servers.net. . 518400 IN NS i.root-servers.net. . 518400 IN NS m.root-servers.net. . 518400 IN NS a.root-servers.net. . 518400 IN NS j.root-servers.net. . 518400 IN NS h.root-servers.net. . 518400 IN NS d.root-servers.net. . 518400 IN NS c.root-servers.net. . 518400 IN NS l.root-servers.net. . 518400 IN NS f.root-servers.net. . 518400 IN NS e.root-servers.net. . 518400 IN NS k.root-servers.net. ;; ADDITIONAL SECTION: a.root-servers.net. 3600000 IN A 198.41.0.4 a.root-servers.net. 3600000 IN AAAA 2001:503:ba3e::2:30 b.root-servers.net. 3600000 IN A 192.228.79.201 c.root-servers.net. 3600000 IN A 192.33.4.12 d.root-servers.net. 3600000 IN A 128.8.10.90 d.root-servers.net. 3600000 IN AAAA 2001:500:2d::d e.root-servers.net. 3600000 IN A 192.203.230.10 f.root-servers.net. 3600000 IN A 192.5.5.241 f.root-servers.net. 3600000 IN AAAA 2001:500:2f::f g.root-servers.net. 3600000 IN A 192.112.36.4 h.root-servers.net. 3600000 IN A 128.63.2.53 h.root-servers.net. 3600000 IN AAAA 2001:500:1::803f:235 i.root-servers.net. 3600000 IN A 192.36.148.17 i.root-servers.net. 3600000 IN AAAA 2001:7fe::53 ;; Query time: 122 msec ;; SERVER: 2001:503:ba3e::2:30#53(2001:503:ba3e::2:30) ;; WHEN: Fri Nov 11 05:59:32 2011 > But I don’t understand where exactly is this limitation exists??? ;; MSG SIZE rcvd: 512 ^^^ Here! > > Please some elaborate on this. > > > Thanks and Regards, > Gaurav Kansal > 9910118448 > > _______________________________________________ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe > from this list > > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
