# Create Outbound Multi-Link elements

Outbound Multi-Link elements group together NetLinks as a single entity and set options for load balancing.

## Before you begin

Configure routing with at least two NetLinks.

To use the round trip time NetLink selection method for load balancing, you must configure the probing settings in the Static NetLink or Dynamic NetLink properties.

##

You can create multiple Outbound Multi-Link elements, and each NetLink can belong to more than one Outbound Multi-Link element at the same time.

To create the Outbound Multi-Link element, you must define the following:

- Which NetLinks are included
- The load-balancing method for determining which link is selected for each new outbound connection
- Whether each NetLink in the Outbound Multi-Link element is an Active or Standby NetLink

The Outbound Multi-Link elements you create do not work on their own; you must use them in the Firewall Policy’s NAT rules to select traffic for outbound load balancing.

Note: If you use element-based NAT, the default NAT address works like an Outbound Multi-Link element. You do not need to create an Outbound Multi-Link element when you use element-based NAT.

For more details about the product and how to configure features, click Help or press F1.

## Steps

1. Select Configuration, then browse to SD-WAN.
2. Browse to Traffic Handlers.
3. Right-click Traffic Handlers, then select New > Outbound Multi-Link.
4. In the Name field, enter a unique name.
5. From the Method drop-down list, select the method for link selection.

## Next steps

Select NetLinks for the Outbound Multi-Link element.

## Outbound Multi-Link Properties dialog box

Use this dialog box to define outbound multi-link properties.

Option | Definition
--- | ---
Name | Specifies the Outbound Multi-Link name.
Category | Categories allow you to flexibly filter your Management Client view.
Select | Opens the Category Selection dialog box.
Comment | An optional comment for your own reference.
Method | Defines the method for link selection. Round Trip Time — The firewall periodically probes the NetLinks to test them for speed and selects the fastest available active NetLink for each new outbound connection. Ratio — Traffic is distributed between all the available active NetLinks according to the relative bandwidth of each NetLink. The NetLink with the highest bandwidth is assigned the largest portion of the traffic.

Option | Definition
--- | ---
Multi-Link Members section
NetLink | Shows the selected Netlink.
Type | Shows whether the Netlink is active or standby. Active — Traffic is routed through the NetLink according to the Method you specify in the Outbound Multi-Link element properties. Standby — Traffic is only routed through the NetLink if all primary (active) NetLinks are unavailable.
Selected Range | Specifies the IP address range for dynamic source address translation (NAT) for the internal source IP addresses on this NetLink.
QoS Classes | Specifies the QoS Classes for traffic handled by the NetLink.
Add | Opens the Multi-Link Member dialog box.
Edit | Opens the Multi-Link Member dialog box for the selected Multi-Link Member.
Remove | Removes the selected Multi-Link Members.

Option | Definition
--- | ---
QoS related settings section
Name | Shows the QoS Class and the Netlink name.
NetLink Role | Shows whether the NetLink is Active or Standy.
Method | The method for link selection. Round Trip Time — The firewall periodically probes the NetLinks to test them for speed and selects the fastest available active NetLink for each new outbound connection. Ratio — Traffic is distributed between all the available active NetLinks according to the relative bandwidth of each NetLink. The NetLink with the highest bandwidth is assigned the largest portion of the traffic. No Load Balancing — Traffic is not balanced between the NetLinks based on the QoS Class.