Configuring Send to Master

Usually, the traffic destined to a VIP reaches the Citrix ADC appliance on which the VIP is active, because an ARP request with the VIP and a VMAC on that appliance has reached the upstream router. But in some cases, such as static routes configured on the upstream router for the VIP subnet, or a topology that blocks this route, the traffic can reach a Citrix ADC appliance on which the VIP is in backup state. If you want this appliance to forward the data packets to the appliance on which the VIP is active, you need to enable the send to master option. This behavior is a per node setting and is disabled by default.

For example, in the following diagram, VIP1 is configured on NS1, NS2, and NS3 and is active on NS1. Under certain circumstances, traffic for VIP1 (active on NS1) may reach VIP1 on NS3. When the send to master option is enabled on NS3, NS3 forwards the traffic to NS1 through NS2 by using route entries for NS1.

Figure 1. An Active-Active Configuration with Send to Master Option Enabled

To enable send to master by using the CLI:

At the command prompt, type:

Example:

> set vrIDParam -sendToMaster ENABLED
 Done

To enable send to master by using the GUI:

1. Navigate to System > Network, in the Settings group, click Virtual Router Parameters.
2. Select the Send to Master option.