Testing the DNS Name Resolution
To verify that your DNS settings are correct and your client or server is able to resolve IP addresses and host names use the
nslookup command. The command is available on Linux and Windows.
To resolve a host name its IP address:
# nslookup DC1.samdom.example.com Server: 10.99.0.1 Address: 10.99.0.1#53 Name: DC1.samdom.example.com Address: 10.99.0.1
To resolve a IP address to its host name:
# nslookup 10.99.0.1 Server: 10.99.0.1 Address: 10.99.0.1#53 220.127.116.11.in-addr.arpa name = DC1.samdom.example.com.
Note that in a Samba AD, the reverse zone is not automatically configured. To set up a reverse zone, see DNS Administration.
Resolving SRV Records
Active Directory (AD) uses SRV records to locate services, such as Kerberos and LDAP. To verify that SRV records are resolved correctly, use the
nslookup interactive shell:
# nslookup Default Server: 10.99.0.1 Address: 10.99.0.1 > set type=SRV > _ldap._tcp.samdom.example.com. Server: UnKnown Address: 10.99.0.1 _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 = 10.99.0.1
- The DNS server is not able to resolve the host name:
** server can't find DC1.samdom.example.com: NXDOMAIN
- The DNS server is not able to resolve the IP address:
** server can't find 18.104.22.168.in-addr.arpa: NXDOMAIN
- The DNS server used is not available:
;; connection timed out; no servers could be reached