Testing the DNS Name Resolution
From SambaWiki
On Windows and *nix, you can use „nslookup“ to test if your computer can resolve records by using your DNS. Try resolving the name of your Domain Controller into its IP:
# nslookup DC1.samdom.example.com Server: 192.168.1.1 Address: 192.168.1.1#53 Name: DC1.samdom.example.com Address: 192.168.1.1
Nslookup will show you, which server was asked (192.168.1.1) and the result of your query (DC1.samdom.example.com has IP 192.168.1.1)
To query a SVR record, you have to start nslookup and set the type to „SRV“, to retrieve the values (works on Windows and *nix):
# nslookup Default Server: UnKnown Address: 192.168.1.1 > set type=SRV > _ldap._tcp.samdom.example.com. Server: UnKnown Address: 192.168.1.1 _ldap._tcp.samdom.example.com SRV service location: priority = 0 weight = 100 port = 389 svr hostname = dc1.samdom.example.com samdom.example.com nameserver = dc1.samdom.example.com dc1.samdom.example.com internet address = 192.168.1.1
If your query can't be answered, because it doesn't exist, you'll receive
** server can't find DC1.samdom.example.com: NXDOMAIN
If you query a none existing DNS server, it would result in
;; connection timed out; no servers could be reached