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Enabling Automatic Configuration of Aruba GRE Tunnel

Aruba GRE is an Aruba proprietary tunnel protocol for encapsulating multicast, broadcast, and L2 packets between Aruba Controller and IAPs. The automatic GRE features uses the IPSec connection between IAP and controller to send the control information for setting up a GRE tunnel. When automatic GRE configuration is enabled, a single IPSec tunnel between the IAP cluster and controller and one or several GRE tunnels are created based on the Per-AP tunnel configuration on the IAP. When this feature is enabled on the IAP, no manual configuration is required on controller to create the GRE tunnel.


Automatic configuration of GRE tunnel is supported only on Aruba controllers. This feature is not supported on controllers running ArubaOS 6.3.x.x or lower versions.

You can configure an IAP to automatically set up a Aruba GRE tunnel from the IAP to Aruba Controller by using Instant UI or CLI.

In the Instant UI

1. Click the More>VPN link at the top right corner of the Instant UI. The Tunneling window is displayed.
2. Select Aruba GRE from the Protocol drop-down list.
3. Enter the IP address or FQDN for the main VPN/IPSec endpoint in the Primary host field.
4. Enter the IP address or FQDN for the backup VPN/IPSec endpoint in the Backup host field. This entry is optional. When you enter Primary host IP address, Backup host IP address, other fields are displayed.
5. Specify the following parameters. A sample configuration is shown in Figure 1.
a. To allow the VPN tunnel to switch back to the primary host when it becomes available again, select Enabled from the Preemption drop-down list. This step is optional.
b. If Preemption is enabled, specify a value in seconds for Hold time. When preemption is enabled and the primary host comes up, the VPN tunnel switches to the primary host after the specified hold time. The default value for Hold time is 600 seconds.
c. To allow the IAP to create a backup VPN tunnel to the controller along with the primary tunnel, and maintain both the primary and backup tunnels separately, select Enabled or Disabled from the Fast failover drop-down list. If the primary tunnel fails, the IAP can switch the data stream to the backup tunnel. This reduces the total failover time to less than one minute.
d. To disconnect all wired and wireless users when the system switches during VPN tunnel transition from primary to backup and backup to primary, set Reconnect user on failover to Enabled.
e. To configure an interval for which wired and wireless users are disconnected during a VPN tunnel switch, specify a value in seconds for Reconnect time on failover within the range of 30—900 seconds. By default, the reconnection duration is set to 60 seconds.
f. Specify a value in seconds for Secs between test packets. Based on the configured frequency, the IAP can verify if an active VPN connection is available. The default value is 5 seconds, which means that the IAP will send one packet to the controller at every 5 seconds.
g. Enter a value for Max allowed test packet loss, to define a number for lost packets, after which the IAP can determine that the VPN connection is unavailable. The default value is 2.
h. Select Enabled or Disabled from the Per-AP tunnel drop-down list. The administrator can enable this option to create a GRE tunnel from each IAP to the VPN/GRE Endpoint rather than the tunnels created just from the master IAP. When enabled, the traffic to the corporate network is sent through a Layer-2 GRE tunnel from the IAP itself and need not be forwarded through the master IAP.

Figure 1  Aruba GRE Configuration

6. Click Next to continue.

In the CLI

To enable automatic confieguration of the GRE tunnel:

(Instant Access Point)(config)# vpn gre-outside

(Instant Access Point)(config)# vpn primary <name/IP-address>

(Instant Access Point)(config)# vpn backup <<name/IP-address>>

(Instant Access Point)(config)# vpn fast-failover

(Instant Access Point)(config)# vpn hold-time <seconds>

(Instant Access Point)(config)# vpn preemption

(Instant Access Point)(config)# vpn monitor-pkt-send-freq <frequency>

(Instant Access Point)(config)# vpn monitor-pkt-lost-cnt <count>

(Instant Access Point)(config)# vpn reconnect-user-on-failover

(Instant Access Point)(config)# vpn reconnect-time-on-failover <down_time>

(Instant Access Point)(config)# end

(Instant Access Point)# commit apply

To view VPN configuration details:

(Instant Access Point)# show vpn config