How to configure DNS in Solaris and AIX?

It is very simple.
Solaris
1) Create /etc/resolv.conf file with your DNS server entries
    Ex:
    bash-2.05$ cat /etc/resolv.conf
                      nameserver 10.999.9.999      #First preference server to look
                      nameserver 10.999.9.999      #Second preference server to look
                      search=domain.comp.net

2) Modify the file /etc/nsswitch.conf
    Look for
      "hosts: files"
    in this file and replace it with
     "hosts: files dns"

Thats it. DNS will be enabled


AIX
1) In /etc/netsvc.conf check for
hosts = local, bind


where the entry "bind" is for dns


2) Modify /etc/resolv.conf file with your DNS server entries

    Ex:

    bash-2.05$ cat /etc/resolv.conf

                      nameserver 10.999.9.999      #First preference server to look

                      nameserver 10.999.9.999      #Second preference server to look

                      search=domain.comp.net

Note: You can use smitty to configure this

Unable to resolve target system name - a DNS problem

I was not able to ping to any machines from my Windows 2003 server. I did following steps to debug & resolve the issue, which was related to a DNS problem.

1) Ping some-server

Unknown host vm-cervino 

2) Ping localhost

Reply from 127.0.0.1: bytes=32 time<10ms TTL=48 (This is working)

3) tracert some-server
Unable to resolve target system name p4server.na.rsa.net. (This gave me a clue that it may be a DNS problem)

4) ping 192.777.77.77 (IP address of some-server)                                                                         
Reply from 192.777.77.77: bytes=32 time=4ms TTL=64 (This confirmed, it is a DNS issue.)

5) I had another Linux machine, where DNS is working fine. I took the working DNS server IP address In Linux machine, DNS configuration is mentioned in /etc/resolv.conf file

6) I configured my Windows Server to working DNS server IP address On Windows server, DNS configuration is mentioned in Start -> Control Panel -> Network Connections -> Local Area Connection -> Properties -> Internet Protocol (TCP/IP) -> Properties -> General tab -> Use the following DNS server addresses -> Preferred DNS server.

After changing Preferred DNS server entry, I was able to connect to machines normally using Domain name.