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estarrFlag for United States of America

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How to dedicate a single NIC for SQL Backup traffic only?


On a physical sql server box I have 4 NICs.   3 of the NIC’s are setup in a NIC team for increased throughput on user connections.  I want to turn on the 4th  NIC and have it isolated for database backup traffic only.  If I give the 4th NIC an IP, how can I be sure that new user connections will not start using this NIC?

I have the ability to configure our third party backup tool (SQLsafe) to run backups over a designated IP.  I’m just not sure how keep sql user connections from accessing it.

Physical box running Win2k8R2, SQL2k8SP1
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EvilPostIt
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If the machine you are copying data to is on a different subnet you should be able to acheive this by adding a static route.
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ASKER

Same subnet.  
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ASKER

Backing up SQL databases over a dedicate NIC is no problem since we are using a third party tool which will allow us to specify the connection IP.  Here's a breakdown of what I'm trying to ask.

Pysical SQL Server NICs
NIC 1: 100.100.10.1 - All sql user connections here and backup traffic here
NIC 2: No address - Want to dedicate backup traffic here, so say I give IP 100.100.10.2

When I give NIC 2 and IP, I think it will also be open to user connections accessing sql server.  How can I prevent this?

I only want to allow our backup server to connect to our sql server using 100.100.10.2.
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ASKER

Thanks for your responses on this!

I think what your saying is I should be able to add a second IP to an instance of sql server and not worry about users connecting on both since they will routed to the IP of the hostname.  I will have to test this and get back to you since I've never added a second IP to an instance of sql server before.

I probably should've change my question to: How to configure two NIC's with different IP's on a box with a single instance of sql server....  And have only one NIC available for user connections.

THanks!
I have worked with many configurations like this in the past and it shouldnt be a problem. Although they were more routing based.
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ASKER

Looks like dual nics on a box running sql server is a  no go.  

"SQL Server does not support multiple IP addresses on the same subnet because this may result in duplicated names on the network." http://support.microsoft.com/kb/244980

The real issue is, I have a 4NIC team setup on a sql server box to write db backups to a DataDomain box.  After months of troubleshooting intermittent performance issues with DD, we're down to thinking its the nic team that DD is having problems with since DD doesn't support LACP.

So what I wanted to do was dedicate 1NIC to datadomain to see if backups ran smoothly.  
And leave the other (3)NIC Team for users so they'd have the increased throughput.

But it doesn't seem possible.  Although I am moving the sql instance into a cluster so maybe that will open up other networking options for me.
But you dont want to support the multiple IP addresses on the same subnet. You wanted to exlude that IP didnt you?

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ASKER

Initially I did want to have 2 IP's on the same subnet.  I was hoping SQL Server had some way of determining what IP an enduser would connect on, and what IP a backupserver would connect on.  Looks like I would need a to setup another network for that to work.
Yeah, that will do the trick. The problem is that as far as SQL Server is concerned both connectioning are user connections so there is no way for it to differentiate between them.
This question has been classified as abandoned and is being closed as part of the Cleanup Program. See my comment at the end of the question for more details.