Re: RAC question, Private IP not really private, any harm?

From: John Hurley <>
Date: Mon, 24 Aug 2009 12:22:39 -0700 (PDT)
Message-ID: <>

On Aug 24, 9:01 am, charles <> wrote:
> Dear Group,
> In our RAC environment, our private IP is not really private, it is
> just another public IP on a different subnet.  PRD can communicate
> with TEST server through private IP through a router.
> I am recommending our network to correct this, but we are in business
> for quite some time without any problem with current configuration.
> Could anybody tell me what is the harm if private IP is not private?
> Thanks

The design goal is to have a separate network ( probably a dedicated switch ) with NICs to each member of the cluster that has as much possible bandwidth as possible ... so that when the RAC database sends traffic between the instances it does so as quickly as possible. Many installations have really high bandwidth setups ( infiniband fabrics ) for these interconnects although others use just dedicated gig switches.

Other places just kind of ignore this recommendation and use existing ports on existing switches.

Are you seeing any wait related issues on the interconnect traffic that faster network connections would eliminate and/or partially alleviate? Received on Mon Aug 24 2009 - 14:22:39 CDT

Original text of this message