You can create a NetMRI failover pair using two NetMRI appliances, in which one acts as the primary appliance and the other as the secondary appliance. A failover pair provides a backup or redundant operational mode between the primary and secondary appliances so you can greatly reduce service downtime when one of them is out of service. You can configure two Operation Center (OC) appliances or standalone appliances to form a failover pair.

In a failover pair, the primary appliance actively discovers and manages network devices and serves the Web UI and the CLI over the shared VIP address while the secondary appliance constantly keeps its database synchronized with the primary. Although you can access a failover pair using either the VIP address of the failover pair or the management IP address of the primary appliance, using the management IP is not recommended because, during a failover, the roles of the primary and secondary appliances reverse, and the management IP becomes unreachable. Accessing the failover pair using the VIP address ensures that you are contacting the active primary appliance. Note that during a failover, all active connections between the NetMRI appliances and the network devices are disrupted, and all ongoing processes fail. Also, all active Web UI and CLI sessions are disrupted during a failover and all users with active sessions must reconnect and log in again after the secondary appliance assumes the role of the primary appliance.

Note the following about the automatic failover feature:

• A failover pair is supported only on NetMRI NT-1400, NT-2200, and NT-4000 (G8-only) appliances. 
• A failover pair is supported on virtual NetMRI appliances in NetMRI 7.5.4 and later releases.
• The primary and secondary appliances must have the same hardware models or VM configurations and software versions.
• The management IP address of the primary and secondary appliances must be on the same subnet.
• The VIP address, which is shared by the primary and secondary appliances, must be on the same subnet as that of the management IP address.

Deploying Automatic Failover for New Appliances

Following are the pre-requisites for deploying automatic failover for new appliances:

• Configure two supported NetMRI appliances with licenses installed.
• Both the appliances must be of the same appliance model and same software version number.
• Provision three IP addresses on the same subnet: a VIP address and two management IP addresses for the appliances.
• If you use the direct replication method to connect two appliances, you need an Ethernet cable to connect the appliances directly through their HA ports. This is applicable only to hardware appliances.
• If you are using the network replication method to connect the appliances, you must connect the systems over a local network and two replication IP addresses must be acquired on the same subnet. You must also select a TCP port for the replication traffic.

To deploy two new Operation Center (OC) or standalone appliances to form a failover pair:

1. Set up and configure two new NetMRI appliances as separate and make sure that the appliances are running NetMRI 7.1.1 or later. 
   For collector failover configuration, make sure that the appliances are running NetMRI 7.1.2 or later. For a failover pair, make sure that the appliances are running NetMRI 7.1.4 or later.
2. Connect both the systems using one of the following methods:
   • Direct replication: You can connect the systems directly through their HA ports. For virtual appliances, direct replication is used in a separate VM-only network that contains only an HA pair.

   • Network replication: You can connect the HA port of both systems to a network using an Ethernet cable. For virtual machines, network replication means a virtual machine in one subnet is connected to a virtual machine in another subnet through a network.

     Infoblox recommends setting up virtual machines (data center or hypervisor) in the same location. If the machines are not set up in the same location, high latency or limited bandwidth can cause unstable performance.

     Infoblox recommends that you connect the systems using the direct replication method.

3. Run the Setup Wizard on both appliances and set the admin password and install the license. The admin password must be the same on both systems. At this point in time, it is not necessary to complete the entire configuration wizard on both systems. You can complete the configuration only on the primary system.
4. If the systems were not shipped with version 7.1.1 or greater, you must upgrade the systems to the latest release.

5. After upgrading both systems to NetMRI 7.1.1 or later, repartition the systems by logging in to the Admin Shell of both the systems and enter the repartition command. For new systems with no network device data collected, you can proceed without resetting and without generating a backup. For systems that are already deployed, and have collected data, follow the steps mentioned in Migrating Existing Systems as Failover Pairs.

   The repartition command applies only to physical appliances.

   
   

6. Choose one system to take the primary role. You can choose the system for which you have completed the entire configuration, otherwise, the configuration might be lost.

7. Log in to the primary system, click the Settings icon > Setup > Failover Configuration, and then specify the configuration settings on in the Failover Configuration page.
   

   After specifying the failover configuration settings and completing the enable operation, the systems start synchronizing data. This process might take up to one hour, depending on the appliance model.

   
   

Migrating Existing Systems as Failover Pairs

You can migrate two existing Operation Center (OC) or standalone appliances to form a failover pair. Ensure that both appliances are running versions NetMRI 7.1.1 or later. To form a collector failover, migrate the existing collector to NetMRI 7.1.2 or later releases.

Following are the pre-requisites for migrating existing systems as a failover pair:

• Two supported NetMRI appliances with licenses. You can choose an existing appliance and a second appliance of the same model.
• Provision two additional IP addresses on the same subnet: a management IP address assigned to each system and a VIP address shared between the failover pair.
• If you use the direct replication method to connect two appliances, you need an Ethernet cable to connect the appliances directly through their HA ports. This is applicable only to hardware appliances.
• If you are using the network replication method to connect the appliances, you must connect the systems over a local network and two replication IPs must be acquired on the same You must also select a TCP port for the replication traffic.

To migrate two existing systems to form a failover pair:

1. Choose an existing NetMRI system and configure a second NetMRI system of the same model.
2. If you are using scan ports, connect the scan ports of the second system to the network in the same way as the existing system.
3. Connect both systems using one of the following methods:

   • Direct replication: You can connect the systems directly through their HA ports. For virtual appliances, direct replication is used in a separate VM-only network that contains only an HA pair.

   • Network replication: You can connect the HA port of both systems to a network using an Ethernet cable. For virtual machines, network replication means a virtual machine in one subnet is connected to a virtual machine in another subnet through a network.

     Infoblox recommends setting up virtual machines (data center or hypervisor) in the same location. If the machines are not set up in the same location, high latency or limited bandwidth can cause unstable performance.

     Infoblox recommends that you connect the systems using the direct replication method.

4. Run the Setup Wizard on the second system and set the admin password and install the license.
5. Exit the Setup Wizard after setting the password and installing the license on the second system.
6. Upgrade the systems to NetMRI 7.1.1, if necessary.
7. After upgrading both systems to NetMRI 7.1.1 or later, repartition the systems to prepare them for automatic failover, as follows:

   • Log in to the administrative shell on the second system and enter the repartition command.  Note that if the system is already partitioned for failover, an error message appears when you run the repartition command.

     The repartition command applies only to physical appliances.

     
     

   • Generate a database archive of your existing system and restore this to the second system. Re-enable SNMP collection after restoring the archive on the second system. To enable SNMP collection, click the Settings icon > Setup > Collection and Groups > Global tab > Network Polling side tab, and then select SNMP Collection.
   • If the data restore is not successful, do not proceed to the next step. If the restore failed due to disk space exhaustion, you may try reducing data retention settings on your existing NetMRI system to reduce the archive size. For more information, refer to the Infoblox NetMRI Administrator Guide or contact Infoblox Support for further assistance. Note that it might take up to 24 hours for reduced data retention settings to take effect.
   • If the data restore is successful, log in to the Admin Shell on the existing system, enter the reset system command, and then enter the repartition command. Note that if the system is already partitioned for failover, an error message appears when you run the repartition command. After repartitioning is complete, run the configure server command, install the license, and then reset the admin password in GUI to match the other system.
8. If you want to use the management IP address of your existing system as the VIP of the failover pair, then you must change the management IP address of the existing system.
9. To configure the second system to take the role of the primary system, do the following:
   • Log in to the second system.
   • Click the Settings icon > Setup > Failover Configuration.
   • Specify the configuration settings on the Failover Configuration page.
10. For an Operation Center, complete the following:
    • Log in to the administrative shell on the Operation Center and run the reset tunserver and configure tunserver commands.  Enter the VIP address of the Operation Center when prompted for the IP address of the Operation Center server.

    • Log in to the administrative shell on each Collector and run the reset tunclient and register tunclient commands. Enter the VIP address of the Operation Center when prompted for the IP address of the Operation Center.

      After specifying the failover configuration settings and completing the enable operation, the systems start synchronizing data. This process might take up to one hour, depending on the appliance model. For details about how to configure these settings, refer to the Infoblox NetMRI Administrator Guide.