Share via

Should we use second network card for SQL Server AlwaysOn AG group private network on VMs?

Sky River 66 Reputation points
2023-02-09T23:51:30.1633333+00:00

We are using VMs for all SQL Servers. Network cards will be virtual as well. When we build AlwaysOn AG group, should we use two network cards for each nodes? One for private which can use for mirror/replication data, one for listener or public?

Or because it is virtual, same as one network card on each server?

Thanks,

Sky

SQL Server on Azure Virtual Machines
SQL Server
SQL Server
A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
12,951 questions
Windows Server Clustering
Windows Server Clustering
Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Clustering: The grouping of multiple servers in a way that allows them to appear to be a single unit to client computers on a network. Clustering is a means of increasing network capacity, providing live backup in case one of the servers fails, and improving data security.
965 questions
0 comments
Accepted answer
  1. Seeya Xi-MSFT 16,451 Reputation points
    2023-02-10T06:07:15.6066667+00:00

    Hi @Sky River ,

    Yes. A public IP address will be used for the Availability Group listener name while the private IP addresses will be used for the Availability Group data replication traffic. This is the best practice.

    Please refer to this blog: Configuring a Dedicated Network for SQL Server Always On Availability Groups Data Replication Traffic

    Best regards,

    Seeya

    If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

    1 person found this answer helpful.
    0 comments

2 additional answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. vipullag-MSFT 25,126 Reputation points
    2023-02-12T02:39:20.0733333+00:00

    Hello Sky River

    Welcome to Microsoft Q&A Platform, thanks for posting your query here.

    It is recommended to use two network cards for each node in the AlwaysOn AG group. One network card should be used for the private network, which can be used for mirroring and replication data. The other network card should be used for the listener or public network.
    This is because it provides better isolation and security for the replication and listener traffic. Additionally, it allows you to configure different network security rules for the different types of traffic.

    However, it is important to note that you can also use a single network card for both the private and public networks, but it is not recommended as it may not provide the same level of isolation and security.

    1 person found this answer helpful.
    0 comments
  2. Edwin M Sarmiento 256 Reputation points
    2023-02-11T01:54:19.61+00:00

    While this article Configuring a Dedicated Network for SQL Server Always On Availability Groups Data Replication Trafficcould be considered best practice, it is mostly applicable to physical machines. With VM, unless you are 100% sure that your vNICs are directly mapped to physical NICs and that they are providing additional bandwidth beyond the physical NICs' teaming capabilities, this is just additional complexity. Same thing when deploying on public cloud infrastructures (AWS, Azure, GCP).

    Keep your configuration as simple as you possibly can.