VRRP Redundancy

The Virtual Router Redundancy Protocol (VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN.) is used to create various redundancy solutions, such as pairs of controllers acting in active-backup mode or in master-standby mode by using a virtual IP address. When the master controller becomes unavailable, a backup controller steps in as the master and takes ownership of the virtual IP address. All network elements (APs and other controllers) can be configured to access the virtual IP address, thereby providing a transparent redundant solution to your network.

VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. eliminates a single point of failure by providing a mechanism to elect a VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master controller. If VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. preemption is disabled (the default setting) and all controllers share the same priority, the first controller that comes up becomes the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master. However, if VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. preemption is enabled and all controllers share the same priority, the controller with the highest IP address becomes the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master.

When you need to change the master-ip on the managed device from interface IP of the active Mobility Master to the vrrp-ip of the Mobility Master, the changes need to be performed in the managed device. The reason this needs to be changed in the managed device is because when the master IP is changed on the managed device, the managed device is not aware if the new master-ip is vrrp-ip of the existing Mobility Master or IP of a new Mobility Master.

Therefore, when you change the master-ip, the setup dialog should be executed on the managed device with write erase followed by deleting the device entry on the Mobility Master for this managed device to start setup-dialogue. This is to avoid issues in the network that will be caused by old setup dialogue which will be maintained in the managed device, if we do not do write erase and brought up managed device cleanly.

ArubaOS supports VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN.-based LMS Local Management Switch. In multi-controller networks, each controller acts as an LMS and terminates user traffic from the APs, processes, and forwards the traffic to the wired network. redundancy in a deployment with active-backup redundancy. In the topology illustrated in Figure 1, when an AP connects to the master controller (M1), the AP receives a standby IP. The standby IP is used by the AP to establish a standby connection to the backup master (M2). If the active master becomes unreachable or reboots, the backup master changes its VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. role to master and accepts active AP connections.

When M1 comes back up, it initially acts as a backup master, and APs associated to M2 establish a standby connection to M1. When the controllers change roles and M1 becomes the active master once again, M2 forces the APs to use M1 as their active master. If an AP has not established a connection to M1 before it disassociates from M2, the AP rebootstraps before it reconnects back to M1.

Figure 1  Redundancy with an Active-Backup Master Controller Pair

Before you Begin

Before you begin configuring VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. redundancy, obtain the following network information:

• VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. ID for the two controllers on the same Layer-2 network.
• Virtual IP address to be used for the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance.

Configuring a Primary and Backup Master for Failover Redundancy

The following procedure configures VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. on the primary and backup master controllers:

1. For a stand-alone controller, under Mobility Controller, select your device and then navigate to the Configuration > Redundancy > L2 redundancy tab.
2. For a managed device, navigate to Configuration > Redundancy > L2 redundancy in the Managed Network node hierarchy.
3. Expand the Virtual Router Table accordion.
4. Click + to add a new virtual router. The New Virtual Router fields appear.
5. Select the IP version from the IP Version drop-down list.
6. Select the VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. on which you want to configure VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. from the VLAN drop-down list.
7. Set Admin State to UP.
8. Specify the priority value in the Priority field. For a backup controller, use the default priority value of 100. For the primary controller, use a priority value higher than the default, such as 110.
9. Configure other VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. parameters as described in Table 1 .
10. Click Submit.
11. Click Pending Changes.
12. In the Pending Changes window, select the check box and click Deploy changes
13.  Repeat steps 1-11 to configure VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. on the other controller in the primary and backup redundant pair.

Table 1: VRRP Configuration Parameters

Parameter	Description
ID	The ID uniquely identifies this VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance. For ease in administration, you should configure this with the same value as the VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. ID.
Description	This is an optional text description to describe the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance.
IP version	Select IPv4 \ IPv6 from the drop-down list box.
Authentication Password	This is an optional password of up to eight characters that can authenticate VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. peers in their advertisements. If this is not configured, there is no authentication password.
Retype authentication password	Reconfirm the password, if configured.
IP address	Based on the selection made in the IP version field, either IP Address \ IPv6 Address is displayed. This is the virtual IP address that will be owned by the elected VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master. Ensure that the same IP address and VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. ID is used on each member of the redundant pair. NOTE: The IP address must be unique and cannot be the loopback address of the device. A maximum of only two virtual IPv6 addresses can be configured on each VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance. Only IPv6 address format is supported for the v6 instance.
IPv6 address	Configure the virtual IPv6 address that will be owned by the elected VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master. Use the same IPv6 address on each member of the redundant pair. This IPv6 address will be redundant - it will be active on the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master, and will become active on the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. backup when the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master fails. NOTE: The IPv6 address must be unique and cannot be the loopback address of the device. A maximum of only two virtual IPv6 addresses can be configured on each VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance. Starting from ArubaOS 8.2.1.0, you can configure a unique local address as the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. IPv6 address on the Mobility Master and the managed devices.
Priority	Priority level of the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance for the device. This value is used in the election mechanism for the master. When configuring VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. on a standby device, use the default priority value of 100. For a master device, use a higher priority value, such as 110.
Advertisement interval (secs)	This is the interval, in seconds, between successive VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. advertisements sent by the current master. The default interval time is recommended. Default: 1 second
Enable router Pre-emption	Selecting this option means that a device can take over the role of master if it detects a lower priority device currently acting as master.
Pre-emption delay (secs)	Specifying a value enables the delay timer. The timer is triggered when the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. state moves out of backup or init state to become a master. This is applicable only if you enable router pre-emption. When the timer is triggered, it forces VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. to wait for a specified period of time, so that all the applications are ready before coming up. This prevents the APs from connecting to the managed device or the stand-alone controller before it can receive them. In the meantime, if there is an advertisement from another VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN., the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. stops the timer and does not transition to master.
Hold Time	Hold time is the number of seconds until which a managed device waits, before starting VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. to account for System or Network convergence delays. Default: 45 seconds NOTE: Configuring the hold time will not take affect if preemption is enabled.
Admin state	Administrative state of the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance. To start the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. instance, change the admin state to UP in the WebUI.
VLAN	VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. on which the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. protocol runs.
Tracking master up-time	(Optional) Perform VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. priority tracking based on how long the device has been the master. This feature is designed to ensure that a master will only be allowed to take and maintain control of the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. if it has been up for a certain amount of minutes (0-1440). This prevents an issue where a device that is periodically going up and down assumes the role of primary master.
Tracking master up-time priority	(Optional) The additional priority given to the master once it has been up for the time interval defined by the Tracking Master Up-time parameter.
Tracking VRRP master state ID	(Optional) Perform tracking based on the UP or DOWN state of another VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master by specifying the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. ID of the master to be tracked.
Tracking VRRP master state priority	(Optional) The priority taken away from a VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master if it is in a DOWN state. The priority levels are returned to their previous state when the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master comes back up.
Tracking VLAN	(Optional) Perform VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. priority tracking based on the UP or DOWN state of a VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN.. Click + below the Tracking VLAN table and specify the following values: VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. Id: ID of the VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. to be tracked. Subtract: Priority level to be subtracted from the device's VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. priority if the tracked VLAN Virtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. goes down.
Tracking interface	(Optional) Perform VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. priority tracking based on the UP or DOWN state of a specific interface. Click + below the Tracking Interface table and specify the following values: Interface: Interface Port to be tracked. Subtract: Priority level to be subtracted from the device's VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. priority if the tracked interface goes down.

Execute the following commands to configure a new virtual router on a stand-alone controller:

Execute the following commands to configure a new virtual router on a managed device:

Configuring APs to use the VRRP IP

Configure the APs associated with the master controller to terminate their tunnels on the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. virtual-IP address . To specify the controller to which an AP or AP group tunnels client traffic, you configure the LMS Local Management Switch. In multi-controller networks, each controller acts as an LMS and terminates user traffic from the APs, processes, and forwards the traffic to the wired network. IP in the AP system profile on the master controller.

The following procedure configures VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. on an AP system profile:

1. For a stand-alone controller, under Mobility Controller, select your device and then navigate to Configuration > System > Profiles tab.
2. For a managed device, navigate to Configuration > System > Profiles in the Managed Network node hierarchy.
3. Under All Profiles > AP, expand AP system.
4. Select the AP system profile for which you want to configure VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN..
5. Expand the LMS Settings accordion and enter the virtual IP address into the LMS IP field.
6. Click Save.
7. Click Pending Changes.
8. In the Pending Changes window, select the check box and click Deploy changes.

The follow procedure configures VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. for an AP group:

1. For standalone controller, under Mobility Controller, select your device and then navigate to Configuration > AP Groups.
2. Select the LMS tab from the selected AP group table.
3. Enter the virtual IP address into the IP address field. For IPv6 address, enter the value in the IPv6 address field.
4. Click Submit.
5. Click Pending Changes.
6. In the Pending Changes window, select the check box and click Deploy changes.

The following CLI Command-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions. commands configure VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. on an AP system profile and applies it to an AP profile and an AP group:

On a stand-alone controller:

On a managed device:

If DNS Domain Name System. A DNS server functions as a phone book for the intranet and Internet users. It converts human-readable computer host names into IP addresses and IP addresses into host names. It stores several records for a domain name such as an address 'A' record, name server (NS), and mail exchanger (MX) records. The Address 'A' record is the most important record that is stored in a DNS server, because it provides the required IP address for a network peripheral or element. resolution is the chosen mechanism for the APs to discover their master controller, ensure that the name aruba-master resolves to the same virtual IP address configured as a part of the master redundancy.

Configuring Master Redundancy and Database Synchronization

In a redundant master controller scenario, you can configure a redundant pair to synchronize their WMS and local user databases. You can either manually or automatically synchronize the databases. When manually synchronizing the database, the active VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. master synchronizes its database with the standby. The command takes effect immediately. When configuring automatic synchronization, you set how often the two controllers synchronize their databases. To ensure successful synchronization of database events, you should set periodic synchronization to a minimum period of 20 minutes.

The following procedure configures master redundancy:

1. For standalone controller, under Mobility Controller, select your device and then navigate to the Configuration > Redundancy > L2 redundancy tab.
2. In the Mobility master node hierarchy, navigate to the Configuration > Redundancy > L2 redundancy tab.
3. Under Master Redundancy, do the following:
4. Enter the VRRP Virtual Router Redundancy Protocol. VRRP is an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. ID to be associated to the master-redundancy pair in the Master VRRP field.
5. Enter the IP address of the redundancy pair in the IP address of peer field.
6. Select the authentication method from the Authentication drop-box.
   1. If IPSec key is selected as an authentication method, enter the IPSec key of the peer and Re-type the key
   2. If Certificate is selected as an authentication method and Factory is selected as the Certificate type, enter thePeer's MAC address
   3. If Certificate is selected as an authentication method and Custom is selected as the certificate type, enter the Peer's MAC address, CA certificate, Server Certificate and select a Suite B algorithm from the drop-down list.
7. Click Submit.
8. Click Pending Changes.
9. In the Pending Changes window, select the check box and click Deploy changes.

The follow CLI Command-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions. commands configure a master redundancy pair. This configuration is applicable on both active and the standby controllers:

The follow CLI Command-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions. commands configure synchronization:

To view the database synchronization settings on the controller, use the following command: