finding authoritative nameservers

[Niall O'Reilly]

On 18 May 2008, at 21:18, Ronald F. Guilmette wrote:

> I've tried all sorts of things, in my abundant ignorance, and nothing
> seems to work entirely reliably 100% of the time.  (Maybe its just
> an impossible goal?)


	Nothing will, if there are ill-configured firewalls or other
	obstacles in the way.  That apart, you can take avoid coding
	by using a well-know tool.

% dig +trace domain-of-interest-here ns

	For example:

dhcp-189(niall)4: dig +trace ucd.ie ns

; <<>> DiG 9.3.4 <<>> +trace ucd.ie ns
;; global options:  printcmd
.                       437919  IN      NS      G.ROOT-SERVERS.NET.
.                       437919  IN      NS      B.ROOT-SERVERS.NET.
.                       437919  IN      NS      I.ROOT-SERVERS.NET.
.                       437919  IN      NS      A.ROOT-SERVERS.NET.
.                       437919  IN      NS      E.ROOT-SERVERS.NET.
.                       437919  IN      NS      H.ROOT-SERVERS.NET.
.                       437919  IN      NS      F.ROOT-SERVERS.NET.
.                       437919  IN      NS      M.ROOT-SERVERS.NET.
.                       437919  IN      NS      D.ROOT-SERVERS.NET.
.                       437919  IN      NS      J.ROOT-SERVERS.NET.
.                       437919  IN      NS      L.ROOT-SERVERS.NET.
.                       437919  IN      NS      K.ROOT-SERVERS.NET.
.                       437919  IN      NS      C.ROOT-SERVERS.NET.
;; Received 492 bytes from 137.43.116.19#53(137.43.116.19) in 42 ms

ie.                     172800  IN      NS      NS2.NIC.FR.
ie.                     172800  IN      NS      ICE.NETSOURCE.ie.
ie.                     172800  IN      NS      GNS2.DOMAINREGISTRY.ie.
ie.                     172800  IN      NS      UUCP-GW-2.PA.DEC.COM.
ie.                     172800  IN      NS      UUCP-GW-1.PA.DEC.COM.
ie.                     172800  IN      NS      NS3.NS.ESAT.NET.
ie.                     172800  IN      NS      NS-IE.RIPE.NET.
ie.                     172800  IN      NS      BANBA.DOMAINREGISTRY.ie.
ie.                     172800  IN      NS      B.IEDR.ie.
ie.                     172800  IN      NS      GNS1.DOMAINREGISTRY.ie.
;; Received 498 bytes from 192.112.36.4#53(G.ROOT-SERVERS.NET) in 151 ms

ucd.ie.                 172800  IN      NS      ns1.tcd.ie.
ucd.ie.                 172800  IN      NS      scsnms.switch.ch.
ucd.ie.                 172800  IN      NS      auth-ns1.ucd.ie.
ucd.ie.                 172800  IN      NS      auth-ns2.ucd.ie.
ucd.ie.                 172800  IN      NS      uucp-gw-1.pa.dec.com.
ucd.ie.                 172800  IN      NS      uucp-gw-2.pa.dec.com.
;; Received 284 bytes from 2001:660:3005:1::1:2#53(NS2.NIC.FR) in 36 ms

ucd.ie.                 86400   IN      NS      scsnms.switch.ch.
ucd.ie.                 86400   IN      NS      auth-ns1.ucd.ie.
ucd.ie.                 86400   IN      NS      auth-ns2.ucd.ie.
ucd.ie.                 86400   IN      NS      uucp-gw-1.pa.dec.com.
ucd.ie.                 86400   IN      NS      uucp-gw-2.pa.dec.com.
ucd.ie.                 86400   IN      NS      ns1.tcd.ie.
;; Received 376 bytes from 134.226.1.114#53(ns1.tcd.ie) in 6 ms

dhcp-189(niall)5:



	Best regards,

	Niall O'Reilly
	University College Dublin IT Services

	PGP key ID: AE995ED9 (see www.pgp.net)
	Fingerprint: 23DC C6DE 8874 2432 2BE0 3905 7987 E48D AE99 5ED9