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How many IP really need for SQL Cluster

  • November 10, 2005 at 7:21 am

    #188433

    Recently, I has an argument with our System group with how many IP it should set for a SQL cluster (active/passive, 1 SQL instance). According to Microsoft, we should have 4,  1 for each node, 1 cluster IP and 1 SQL IP. Our server group is arguing that we can combine cluster IP and SQL IP as one. I can't find a good reason to against it. I aslo search the Microsoft did not find any reason explain why we need 4 instead of 3. Can someone shed some light on this...

  • November 10, 2005 at 9:56 am

    #603272

    I though you would need 5 IP , 1 for each node, 1 private for each node, 1 for the cluster.  The cluster also will be use by SQL.  It is easier to manage when you have the cluster and SQL using the same name.

     

    mom

  • November 11, 2005 at 4:11 am

    #603384

    IN THEORY (and i really do mean that!), your systems group is correct ... but arranging your cluster groups to achieve this would be an appauling configuration and i'm sure you could find some cluster best practices guides that would tell you why. (The main "Cluster Group" should be independent of all other resources!)

    What you would have to do is merge the "Cluster Group" and "SQL Server Groups", and make the "SQL Server Network Name" Resource dependent on the "Cluster IP" Resource rather than its' own IP Resource. Trust me when i say i've never tried to do this ... hence it being theorectical, but the theory is good!

    THIS WOULD BE AN TERRIBLY BAD IDEA!!!

    Strangely, Microsoft are correct and you need a minimum of 4 Public IP addresses to setup a stable SQL Cluster ... so 192.168.1.10 and 11 for nodes 1 and 2, .12 for the Cluster IP and .13 for the SQL Server IP. So i'm afraid you'll have to upset your Systems Group and tell them ur stealing 4 IP's from their pool.

    The private network link doesn't (and probably shudn't!) need to use IP's from the Public pool and you can use pretty much anything you like ... but using something like 10.1.1.1 and .2 on this link is fairly standard (Class B with an obviously different subnet mask, so minimal routing problems!)

    For the sake of 1 IP address, just argue that u'd prefer to have a stable (and more flexible!) Cluster ... or make sure that its THEM that does the merging of the Cluster Groups ... basically, if they're gonna be that tight, you may as well have fun and throw in some torture for the hell of it!?

    To be frank, if ur systems group cant spare one extra IP address from an entire Class C address space, then they're either doing summat wrong or need to shift to Class B!?

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