SQL 2012 Availability Group Replication - Can you control which network is used for replication traffic?

Question

Hi All,

Hoping to get some guidance around network configuration of SQL 2012 Availability Groups.  I know that with Exchange 2010; the network used for replication can be specified on the DAG; is there a similar configuration option available for SQL 2012 Availability Group / Cluster that traverse two data centre's as we would like to force replication traffic across a dedicated link for that purpose.

Example:

10.0.0.0/24 (Site A),10.0.1.0/24 (Site B) - All Client Traffic and Cluster Heartbeat (No Replication Traffic)

172.16.1.0/28 (Stretched Subnet Site A and Site B; Dedicated Intersite Link) - Replication and Cluster Heartbeat Traffic No Client Traffic

Any clarification or guidance would be much appreciated.

Kind Regards,

Hayden

Answer 1

Hi TheFitz,

I never did this but i think the below plan can be tested:

Add that dedicated network to your SQL Cluster Group- create required dependency.

NOw configure SQL to listen to a specific port on that IP too.

NOw configure what-ever you want to using that particular IP\Port.

DO let me know your thoughts on this.

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Sarabpreet Singh Anand

Blog , Personal website

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Answer 2

During the AlwaysOn Availability Group creation wizard there is a section that has some tabs.  On of the tabs says something like "endpoints" or something like that.  The default entry here is the FQDN and a port number.  If you replace the FQDM with the IP you want to use you can force replication traffic to use whatever network you desire.

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David A. Bermingham, MVP, Senior Technical Evangelist, SIOS Technology Corp

Answer 3

Thank you both for your replies; I will test the above and post the results.  One question though; Are the endpoints themselves specific to the availability group; will setting those endpoints to another network affect the client facing side of the Availability group on a different subnet?

i.e. SQLAG01:1433 -> 10.0.0.50
Will the client traffic still flow to the 10.0.0.x addresses on the SQL servers?  I am hoping to limit only the Replication traffic to the other network as the 172.16.1.x network will have no gateway addresses.

Kind Regards,

HaydeN

Answer 4

As Suggested earlier also, SQL Server can be configured on multiple networks and it will listen on Each IP. 

NOw while configuring AlwaysON you can mention IP1 which is known only to you and you can expose only IP2 to clients to connect - This way you can segregate the load\traffic.

I think this will work\help.

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Sarabpreet Singh Anand

Blog , Personal website

This posting is provided , "AS IS" with no warranties, and confers no rights.

Please remember to click "Mark as Answer" and "Vote as Helpful" on posts that help you. This can be beneficial to other community members reading the thread.