# Create NetLink elements for Multi-Link configuration

NetLink elements usually represent Internet connections, but you can also use NetLinks to represent other network connections. You can use NetLinks to define alternative routes that lead to the same destination IP addresses.

##

Although some NetLink element settings are optional, we recommend that you configure all settings for a fully functional configuration.

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 > Static NetLink or New > Dynamic NetLink.
4. Configure the settings, then click OK.

## Static NetLink Properties dialog box

Use this dialog box to define Static NetLink elements.

Option | Definition
--- | ---
General tab
Name | The name of the element.
Gateway | Specifies the next-hop Gateway the NetLink uses. The Gateway is usually added as a Router element, but you can also choose another Firewall according to your network configuration.
Network | Specifies the address space that the ISP has assigned to your organization. Click Select to select an element. Do not select the Any Network element for the NetLink. Select or create Network elements that represent the specific public IP addresses assigned by your ISP and that are routed to the Internet provider’s router.
DNS IP Addresses (Optional) | Specifies the IP addresses of the DNS servers that resolve DNS requests sent from the interface with which the NetLink is associated. These NetLink-specific DNS servers provide DNS services only when using valid IP addresses in the address space that the ISP has assigned to your organization. Note: To use NetLink-specific DNS IP addresses, you must configure DNS Relay for the firewall. Note: DNS IP addresses configured in the Engine Editor can override this setting. Click Add to add an element to the table, or Remove to remove the selected element. IP Address — Adds an IP Address element that represents a single IP address. Network Element — Adds a Network element that represents a network space.
Provider Name | Specifies the name of the Internet service provider.
Connection Type | Select a Connection Type element to define how the NetLink is used in a Multi-Link configuration.
Download Speed or Upload Speed (Required for ratio-based load-balancing) | Enter the actual bandwidth that this connection provides. For example, if the stated speed of the connection is 50 Mbit/s, but the connection provide a maximum speed of 30 Mbit/s, enter 30 Mbit/s. These speeds are used in ratio-based load-balancing to calculate how much traffic each link receives in relation to the other links. These speeds are also used to calculate the link status in the SD-WAN dashboard in the Home view. The capacity of each link is used to determine the total capacity of all the links. The current traffic load for each link is shown as a percentage of the total capacity of all links.
IPv4 Outbound Address or IPv6 Outbound Address (Optional) | To override the default NAT address for traffic from internal networks that is specified in the element-based NAT settings, enter an IP address. If you specify both an IPv4 address and an IPv6 address, the correct type of address is automatically selected based on the traffic. If you do not specify an IP address, the IP address of the corresponding network is automatically selected based on routing. On NGFW Engine clusters, the CVI address of the corresponding network is used.
Category (Optional) | Includes the element in predefined categories. Click Select to select a category.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Probing tab
Probe IP Addresses (Required when using active and standby NetLinks) | Shows the IP addresses that are probed with ICMP echo requests (ping) to determine if the link is up. We recommend entering more than one address to avoid excluding the link if the host that is probed goes down. Select addresses that give reliable results of end-to-end connectivity to destinations that need to be reached through the NetLink, such as a remote server reached through the Internet. Click Add to add a row to the table, or Remove to remove the selected row.
Active Mode (Required when using active and standby NetLinks) | Specifies the probe period and timeout in seconds when Active Mode is used. Period — Specifies the probe period in seconds. Timeout — Specifies the probe timeout in seconds.
Standby Mode (Required when using active and standby NetLinks) | Specifies the probe period and timeout in seconds when Standby Mode is used. Timeout — Specifies the probe timeout in seconds. Period — Specifies the probe period in seconds.

## Dynamic NetLink Properties dialog box

Use this dialog box to define dynamic NetLink elements.

Option | Definition
--- | ---
General tab
Name | The name of the element.
Provider Name | Specifies the name of the Internet service provider.
Connection Type | Select a Connection Type element to define how the NetLink is used in a Multi-Link configuration.
Learn DNS IP Addresses Automatically | When selected, the NetLink automatically learns the IP addresses of the Internet service provider's DNS servers.
Download Speed or Upload Speed (Required for ratio-based load-balancing) | Enter the actual bandwidth that this connection provides. For example, if the stated speed of the connection is 50 Mbit/s, but the connection provide a maximum speed of 30 Mbit/s, enter 30 Mbit/s. These speeds are used in ratio-based load-balancing to calculate how much traffic each link receives in relation to the other links. These speeds are also used to calculate the link status in the SD-WAN dashboard in the Home view. The capacity of each link is used to determine the total capacity of all the links. The current traffic load for each link is shown as a percentage of the total capacity of all links.
Category (Optional) | Includes the element in predefined categories. Click Select to select a category.
Comment (Optional) | A comment for your own reference.

Option | Definition
--- | ---
Probing tab
Probe IP Addresses (Required when using active and standby NetLinks) | Shows the IP addresses that are probed with ICMP echo requests (ping) to determine if the link is up. We recommend entering more than one address to avoid excluding the link if the host that is probed goes down. Select addresses that give reliable results of end-to-end connectivity to destinations that need to be reached through the NetLink, such as a remote server reached through the Internet. Click Add to add a row to the table, or Remove to remove the selected row.
Active Mode (Required when using active and standby NetLinks) | Specifies the probe period and timeout in seconds when Active Mode is used. Period — Specifies the probe period in seconds. Timeout — Specifies the probe timeout in seconds.
Standby Mode (Required when using active and standby NetLinks) | Specifies the probe period and timeout in seconds when Standby Mode is used. Timeout — Specifies the probe timeout in seconds. Period — Specifies the probe period in seconds.