10 Replies Latest reply: Apr 11, 2013 1:55 AM by Pradeepcmst RSS

    Private,Public and Virtual IP in RAC

    Chamkor Singh
      Hi All,

      I wanted to know the importance of Private,Public and Virtual IP in RAC and what role it plays in Oracle RAC.

      regards
      Vijay
        • 1. Re: Private,Public and Virtual IP in RAC
          P.Forstmann
          Short answer:

          1. private IP address is used only for internal clustering processing (Cache Fusion) (aka as interconnect)
          2. VIP is used by database applications to enable fail over when one cluster node fails
          3. public IP adress is the normal IP address typically used by DBA and SA to manage storage, system and database.

          Edited by: P. Forstmann on 19 nov. 2010 09:51
          • 2. Re: Private,Public and Virtual IP in RAC
            816473
            Public Interface – Used for normal network communications to the node

            Virtual (Public) Interface – Used for failover and RAC management

            Private Interface – Used as the cluster interconnect.

            Using virtual IP we can save our TCP/IP timeout problem because Oracle notification service maintains communication between each nodes and listeners. Once ONS found any listener down or node down, it will notify another nodes and listeners with same situation. While new connection is trying to establish connection to failure node or listener, virtual IP of failure node automatically divert to surviving node and session will be establishing in another surviving node. This process doesn't wait for TCP/IP timeout event. Due to this new connection gets faster session establishment to another surviving nodes/listener.
            • 3. Re: Private,Public and Virtual IP in RAC
              Chamkor Singh
              Hi

              Thanks for your prompt revert.

              1. private IP address is used only for internal clustering processing (Cache Fusion)
              2. VIP is used by database applications to enable fail over when one cluster node fails
              3. public IP adress is the normal IP address typically used by DBA and SA to manage storage, system and database.

              Can you throw more light on Public IP.Does that mean we cant use Private and VIP to manage the 3rd point mentioned by you???

              regards
              Vijay
              • 4. Re: Private,Public and Virtual IP in RAC
                Pavan Kumar
                Hi,
                Can you throw more light on Public IP.Does that mean we cant use Private and VIP to manage the 3rd point mentioned by you???
                Can you consider the case where your public ip -which is using by public world or middle tier application layer, which would not be feasible to use by ORACLE application in order to manage the transfer of blocks across the cache fusion (just minor functionality of cache fusion).

                we should not use, so we are going for dedicate private network with high band width across the nodes.

                - Pavan Kumar N

                Edited by: Pavan Kumar on Nov 19, 2010 2:28 PM
                • 5. Re: Private,Public and Virtual IP in RAC
                  Chamkor Singh
                  Hi,

                  Thanks all for your clarifications.Just one more thing,if my application has to connect to database,it would be connecting thru which IP ? Public or VIP.I suppose both can be used.If we want to connect to a specific instance of 2node,then probably we can use public IP.Kindly correct me if wrong..

                  regards
                  Vijay
                  • 6. Re: Private,Public and Virtual IP in RAC
                    Pavan Kumar
                    Hi,

                    Usually applications should connect to VIP - planned for HA Mechanism. It's better to connect to VIP instead of public. For Performance checks or for some administration task you can connect with public Ip's.

                    - Pavan Kumar N
                    • 7. Re: Private,Public and Virtual IP in RAC
                      Chamkor Singh
                      Thanks Pavan.I have got my clarifications.

                      Regards
                      Vijay
                      • 8. Re: Private,Public and Virtual IP in RAC
                        user8336357
                        I have installed 11gR2 RAC on RHEL. During the installation, never it did prompt me to enter any private IP or alias. How 11gR@ RAC know to use private inter connector if the information never fed to it?

                        James
                        • 9. Re: Private,Public and Virtual IP in RAC
                          971394
                          You can add your private-IP address in etc/hosts file itself.


                          Regards,
                          Sarathi
                          • 10. Re: Private,Public and Virtual IP in RAC
                            Pradeepcmst
                            Hi,
                            You can mention the private IP address in etc/hosts file if you are using oracle version prior to 11.2.0.. But in 11g release 2 version, we no need to mention the private IP address in /etc/hosts file , since its managed by themselves( which we ll provide the private network info during installation).