I run nslookup in my Windows 2000 Pro workstation and the following message
appears:

C:\>nslookup
1.0.168.192.in-addr.arpa
primary name server = domain.com
responsible mail addr = root.1.0.168.192.in-addr.arpa
serial = 2005051631
refresh = 10800 (3 hours)
retry = 3600 (1 hour)
expire = 604800 (7 days)
default TTL = 86400 (1 day)
*** Domain name server can not be found for address 192.168.0.1: No
information
DNS request timed out.
timeout was 2 seconds.
*** Default servers are not available
Default server: UnKnown
Address: 192.168.0.1


Why the server can not be found?

Why the default server is unknown?

Any help would be appreciated.