--- author: VanMSFT ms.author: vanto ms.date: 08/25/2022 ms.prod: sql ms.technology: linux ms.topic: include --- ## Considerations for multiple Network Interfaces (NICs) When setting up high availability with servers that have multiple NICs, follow these suggestions: - Make sure the `hosts` file is set up so that the server IP addresses for the multiple NICs resolve to the hostname of the Linux server on each node. - When setting up the cluster using Pacemaker, using the hostname of the servers should configure Corosync to set the configuration for all of the NICs. We only want the Pacemaker/Corosync communication over a single NIC. Once the Pacemaker cluster is configured, modify the configuration in the `corosync.conf` file, and update the IP address for the dedicated NIC you want to use for the Pacemaker/Corosync communication. - The `` given in the `corosync.conf` file should be the same as the output given when doing a reverse lookup (`ping -a `), and should be the short name configured on the host. Make sure the `hosts` file also represents the proper IP address to name resolution. The changes to the `corosync.conf` file example are highlighted below: 
  nodelist {
    node {
        ring0_addr: ip_address_of_node1_NIC1
        name: hostname_of_node1
        nodeid: 1
    }
    node {
        ring0_addr: ip_address_of_node2_NIC1
        name: hostname_of_node2
        nodeid: 2
    }
    node {
        ring0_addr: ip_address_of_node3_NIC1
        name: hostname_of_node3
        nodeid: 3
    }
  }