RAC Virtual IP

At first installation of Oracle 10g RAC which i’ve seen, made by an Oracle consultant about two years ago (version on Linux Suse EL on x86_64 platform) , the network configuration of Operating System were as this:

eth0: private interconnection interface
eth1:”public” interface

apart from the fact that also with 10.2 release VIPCA complains that “public” interface has not a pubblic class IP, i’ve noticed another problem that i don’t know how to resolve: virtual IP is being created on first interface without possibility to change it, that is “eth0” that is the private interface. In a correct configuration such interface would be connected to a switch with other private interfaces of other nodes of the cluster, separated from “public” network to which would be connected “public” interface. With such architecture i would have:

eth0: private interconnection interface
eth1:”public” interface

VIP on eth0, on network card attached on private switch, not reachable from clients connected to public switch. NO GOOD. The only workaround that i’ve found is to reconfigure operating system (in new installations) to put private ip on lower interfaces (eth0) and public IP on higher interfaces.

Do anybody know a remedy for my first installation? Note, in that installation all interfaces are connected to the same switch and so all goes well. Something is not as high available as it may be, there are not redundant network interfaces.


4 Responses to “RAC Virtual IP”

  1. Oracle Database Exchanging Experiences RAC Virtual IP: Correction « Says:

    […] 2007 — oracledb I’ve studied. Yes i was not completely correct in my previous post on RAC Virtual IP because i’m guilty of not RTFM. It appens, there are thousand of manual pages. So, in […]

  2. v Says:

    why is there no virtual cluster ip for the oracle rac unlike in the case of oracle failsafe?
    Can such a virtual cluster ip/name be set for the nodes in a rac so that this virtual cluster name can be specified to refer to any one of the nodes there by providing fault tolerance at os level too ?

  3. oracledb Says:

    v, in the case of oracle Failsafe there is only one node active in any moment, so it is normal to have only one virtual IP. With RAC there are two or more (it depends on how many active nodes there are in the RAC) active nodes, every one has to have one ip and the cannot have the same IP. Theoretically you can elect and use one of these IP’s as the cluster (and unique) virtual IP, then Oracle listener redirection mechanism can do both the load balancing and fail safe (fault tolerance). The method of TNSNAMING with all virtual IP’s in the string alias gives you more options.
    I hope to have explained my point.

  4. oracledb Says:

    I’m not sure to have well understood your last question, but i want add something to what i’ve said above. Such load balancing applies only to oracle database, if you use such VIP with other applications, there is no load balancing because that load balancing has to be application dependent.

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