# Defining MD5 keys for OSPF virtual links

Use the following procedure to configure OSPF MD5 keys for OSPF virtual interfaces.

## Prerequisites

- Install the Advanced License.

- Enable IP routing globally on the switch.

- Assign an IP address to the VLAN that you want to enable with OSPF.

  Routing is automatically enabled on the VLAN when you assign an IP address to it.

## Procedure steps

1. From the navigation tree, double-click IP Routing.

2. In the IP Routing tree, double-click OSPF.

3. In the work area, click the Virtual If Message Digest tab.

4. In the toolbar, click Insert.

5. Configure the parameters as required.

6. Click Insert.

## Variable definitions

The following table describes the fields of the Virtual If Message Digest tab.

Field | Description
--- | ---
AreaId | Specifies the area ID of the area associated with the virtual interface.
Neighbor | Specifies the IP address of the neighbor router associated with the virtual interface.
Index | Specifies the index value of the virtual interface message digest entry. The value is an integer between 1 and 255.
Type | Specifies the type of digest entry. Only MD5 is supported.
Key | Specifies the key value associated with the digest entry.