3 Replies Latest reply: Apr 15, 2012 2:49 AM by 912595 RSS

    DNS server and SCAN Name with Oracle RAC

    Neo-b
      Hello All,

      I am installing Oracle RAC 11gR2
      I want to configure a DNS server to resolve my VIP's and my SCAN NAME.

      I will configure DNS service from windows 2003 to be as my DNS server.

      My question is how my clients (database clients) will know which DNS server should they access to get oneIP from the three SCAN NAME IPs?

      I define the SCAN name in the tnsnames of each client, but how they know what DNS server should they access to get the corresponding SCAN VIP?


      should the DNS server be defined in the TCP/IP settings of each client ??

      Regards,
        • 1. Re: DNS server and SCAN Name with Oracle RAC
          onedbguru
          If you want your clients to actually translate the DNS entry and find the correct "address", the answer is YES.
          • 2. Re: DNS server and SCAN Name with Oracle RAC
            Neo-b
            Simply I want to work with the Oracle RAC standards.

            Oracle RAC will use the scan name in the tnsnames, so my question how the scan name and how should I tell my clients which DNS to resolve.

            Regards,
            • 3. Re: DNS server and SCAN Name with Oracle RAC
              912595
              NB wrote:
              Hello All,

              I am installing Oracle RAC 11gR2
              I want to configure a DNS server to resolve my VIP's and my SCAN NAME.

              I will configure DNS service from windows 2003 to be as my DNS server.

              My question is how my clients (database clients) will know which DNS server should they access to get oneIP from the three SCAN NAME IPs?
              DNS is configured in network as a whole in LAN, so wil configuring DNS in your network you server have the entry of DNS in /etc/hosts. So every machine who is under this network will resolve the VIP address from this DNS
              >
              I define the SCAN name in the tsunamis of each client, but how they know what DENS server should they access to get the corresponding SCAN VIP?
              Database clients doesn't need to know which DENS server to use. You specify 3 SCAN VIPs in DENS with one SCAN Name
              When you slipup scan name, it gives you 3 VIPs against it in round robin.

              So you specify SCAN Name in tnsnames.ora, when database client make a connection, it picks up the scan name of it and enter into your network.But SCAN name further resolves to 3 VIPS so it picks up one VIP and connects to ip. This SCAN VIP has SCAN Listener running on any of the machine in cluster. SO when this listener receives the request, it further connects to Local mahine of RAC through Local listener.

              See - http://www.oracle.com/technetwork/database/clustering/overview/scan-129069.pdf
              Linux: How to Configure the DNS Server for 11gR2 SCAN [ID 1107295.1]
              DNS and DHCP Setup Example for Grid Infrastructure GNS [ID 946452.1]
              11gR2 Grid Infrastructure Single Client Access Name (SCAN) Explained [ID 887522.1]