Windows clustering between different subnet

Question

_{Monday, September 17, 2012 5:13 PM}

Hi, I am absolutely new to clustering technology. As for our company system concern, cluster has to be in two separate subnet. If it is possible at all, could anyone give the documentation and blogs link please?

Thanks

Raofu

All replies (6)

_{Tuesday, September 18, 2012 12:30 AM ✅Answered | 1 vote}

Here's a blog post and configuration steps for Windows Server 2008. Multi-subnet support is also in Windows Server 2012.

http://blogs.msdn.com/b/clustering/archive/2011/08/31/10204142.aspx

The main thing you need to confirm is if your clustered application supports multi-subnets. For example, older versions of SQL Server don't.

_{Tuesday, September 18, 2012 3:17 AM ✅Answered | 1 vote}

Hi,

I agree with above poster, Server Cluster support node in different subnet, but the applications or services hosted in the cluster may not support multi-subnet.

A multi-site cluster running Windows Server 2008 can contain nodes that are in different subnets, unless it is a cluster running SQL Server 2005 or SQL Server 2008 (which requires the use of a virtual local area network or VLAN). In other words, the cluster nodes can potentially communicate across network routers. However, when using multiple subnets, it is important to consider how clients will discover services or applications that have just failed over.

Although a clustered service or application keeps the same network name after failover, if it fails over to a server in a different subnet, that network name will then be associated with a new IP address. The DNS servers must update one another with this new IP address before clients can discover the service or application that has failed over. In addition, on the client, the cached DNS entries need to expire before the client queries a DNS server again. In other words, with multiple subnets, the amount of downtime that clients experience is dependent not just on how quickly failover occurs, but also on how quickly DNS replication occurs and how quickly the clients query for updated DNS information.

To minimize downtime in a multi-site cluster, consider the following approaches:

• Review your options for using VLANs and for using multiple subnets to connect the nodes. Each approach has its advantages (but note that a cluster running SQL Server 2008 must be configured with a VLAN). One of the advantages for VLANs is that they avoid issues associated with the time it takes for DNS replication to complete. However, multiple subnets can be simpler than VLANs to set up and manage.
• If you prefer to use multiple subnets in your multi-site cluster, you might choose to modify two private properties associated with the network name resources in your cluster. One property is the Time to Live (TTL) property, which can limit the amount of time that a given DNS record is used before it will be discarded, that is, limit the persistence of DNS information that might be stale because a failover occurred. The default Time to Live is 20 minutes or 1200 seconds, but you can limit it according to recommendations for your application. (For example, the recommended value for Exchange Server 2007 is 5 minutes or 300 seconds.)
• The other private property that you might choose to modify controls which IP addresses are registered in DNS: either all IP addresses on which a network name resource depends, or only the IP address that successfully comes online (that is, the IP address on the subnet of the node that currently owns that network name resource). If you register all IP addresses on which a network name resource depends, any IP address that is needed by a network name will always be registered (regardless of subnet), minimizing downtime. This private property is most useful when the client side of your client-server application is capable of handling DNS records with multiple IP addresses associated with the network name.

For more information please refer to following MS articles:

Requirements and Recommendations for a Multi-Site Failover Cluster
http://technet.microsoft.com/en-us/library/dd197575(v=WS.10).aspx
SQL Server Multi-Subnet Clustering
http://technet.microsoft.com/en-us/library/ff878716(v=sql.110).aspx

Lawrence

TechNet Community Support

_{Wednesday, September 19, 2012 2:22 AM ✅Answered}

A quick search on TechNet turns up this - http://technet.microsoft.com/en-us/library/a5e5fc11-97db-48b2-85fb-f5780822a26f.  Is that what you are looking for?

tim

_{Wednesday, September 19, 2012 2:47 AM ✅Answered}

Hi,

Thanks “Tim Cerling” provide the web link. That the link to set up Cluster in Multi-Site, just note that remove dot mark at end of the link.

Checklist: Setting Up a Clustered Service or Application in a Multi-Site Failover Cluster
http://technet.microsoft.com/en-us/library/a5e5fc11-97db-48b2-85fb-f5780822a26f

For more step by step guide you may refer to this link:

Getting Started: Failover Clusters
http://technet.microsoft.com/en-us/library/ff182317(v=ws.10).aspx

This link describes 5 scenarios; these guides also apply to Multi-Site Server cluster scenario:

Failover Cluster Step-by-Step Guide: Validating Hardware for a Failover Cluster

Failover Cluster Step-by-Step Guide: Configuring a Two-Node File Server Failover Cluster

Failover Cluster Step-by-Step Guide: Configuring a Two-Node Print Server Failover Cluster

Failover Cluster Step-by-Step Guide: Configuring the Quorum in a Failover Cluster

Failover Cluster Step-by-Step Guide: Configuring Accounts in Active Directory

Lawrence

TechNet Community Support

_{Tuesday, September 18, 2012 1:24 PM}

Lawrence

this document only discuss the requirement of multi subnet cluster. I am wondering to know is it differnet from usual clustering of 2008 server. or I need to do some addtional configuration for multi subnet clustering.

Is there any step by step guide for multisubnet similar to two node step by step guide?

I would be grateful.

Thanks.

_{Friday, September 21, 2012 5:01 PM}

thank you everyone. these are enogh guidelines for me. i hope i can get it done.