This website is super useful for verifying and testing SPF records :
SPF Syntax Validator : http://vamsoft.com/support/tools/spf-syntax-validator
SPF Policy Tester : http://vamsoft.com/support/tools/spf-policy-tester
May 12, 2014
SPF Policy Tester & Syntax Validator
May 17, 2010
How to check domain NS glue records using dig
Lets check microsoft.com NS glue records by dig command.
As it is a .com domain first we should check root servers for .com by the following command :
dig NS com
Result :
com. 22124 IN NS d.gtld-servers.net. com. 22124 IN NS f.gtld-servers.net. com. 22124 IN NS a.gtld-servers.net. com. 22124 IN NS c.gtld-servers.net. com. 22124 IN NS g.gtld-servers.net. com. 22124 IN NS i.gtld-servers.net. com. 22124 IN NS l.gtld-servers.net. com. 22124 IN NS m.gtld-servers.net. com. 22124 IN NS k.gtld-servers.net. com. 22124 IN NS e.gtld-servers.net. com. 22124 IN NS h.gtld-servers.net. com. 22124 IN NS b.gtld-servers.net. com. 22124 IN NS j.gtld-servers.net.
We can choose any root server for next query , I will choose m.gtld-servers.net :
dig NS microsoft.com @m.gtld-servers.net
Result :
;; AUTHORITY SECTION: microsoft.com. 172800 IN NS ns1.msft.net. microsoft.com. 172800 IN NS ns2.msft.net. microsoft.com. 172800 IN NS ns3.msft.net. microsoft.com. 172800 IN NS ns4.msft.net. microsoft.com. 172800 IN NS ns5.msft.net. ;; ADDITIONAL SECTION: ns1.msft.net. 172800 IN A 65.55.37.62 ns2.msft.net. 172800 IN A 64.4.59.173 ns3.msft.net. 172800 IN A 213.199.161.77 ns4.msft.net. 172800 IN A 207.46.75.254 ns5.msft.net. 172800 IN A 65.55.226.140
OK we are done , the ADDITIONAL SECTION in last query contains the glue records :
ns1.msft.net. 172800 IN A 65.55.37.62 ns2.msft.net. 172800 IN A 64.4.59.173 ns3.msft.net. 172800 IN A 213.199.161.77 ns4.msft.net. 172800 IN A 207.46.75.254 ns5.msft.net. 172800 IN A 65.55.226.140