Configure dual APNs

Some cellular carriers offer a dual APN feature that allows a SIM card to be provisioned with two separate APNs that can be used simultaneously. For example, Verizon offers this service as its Split Data Routing feature. This feature provides two separate networking paths through a single cellular modem and SIM card, and allows for configurations such as:

Segregating public and private traffic, including policy-based routes to ensure that your internal network traffic always goes through the private connection.
Separation of untrusted Internet traffic from trusted internal network traffic.
Secure connection to internal customer network without using a VPN.
Separate billing structures for public and private traffic.
Site-to-site networking, without the overhead of tunneling for each device.

In the following example configuration, all traffic on LAN1 is routed through the public APN to the internet, and all traffic on LAN2 is routed through the private APN to the customer's data center:

To accomplish this, we will create separate WWAN interfaces that use the same modem but use different APNs, and then use routing roles to forward traffic to the appropriate WWAN interface.

 Web

Log into Digi Remote Manager, or log into the local Web UI as a user with full Admin access rights.
Access the device configuration:
Remote Manager:
1. Locate your device as described in Use Digi Remote Manager to view and manage your device.
2. Click the Device ID.
3. Click Settings.
4. Click to expand Config.
Local Web UI:
1. On the menu, click System. Under Configuration, click Device Configuration.
  The Configuration window is displayed.
Increase the maximum number of interfaces allowed for the modem:
1. Click Network > Modems > Modem.
2. For Maximum number of interfaces, type 2.
Create the WWAN interfaces:
In this example, we will create two interfaces named WWAN_Public and WWAN_Private.
1. Click Network > Interfaces.
2. For Add Interface, type WWAN_Public and click .
3. For Interface type, select Modem.
4. For Zone, select External.
5. For Device, select Modem .
6. (Optional) For APN selection, select whether you want to configure the device to use the preconfigured APNs, custom APNs, or both.
7. For Add Interface, type WWAN_Private and click .
8. For Interface type, select Modem.
9. For Zone, select External.
10. For Device, select Modem .
  This should be the same modem selected for the WWAN_Public WWAN.
11. For APN selection, select whether you want to configure the device to use the preconfigured APNs, custom APNs, or both.
Create the routing policies. For example, to route all traffic from LAN1 through the public APN, and LAN2 through the private APN:
1. Click Network > Routes > Policy-based routing.
2. Click the  to add a new route policy.
3. For Label, enter Route through public APN.
4. For Interface, select Interface: WWAN_Public.
5. Configure the source address:
  1. Click to expand Source address.
  2. For Type, select Interface.
  3. For Interface, select LAN1.
6. Configure the destination address:
  1. Click to expand Destination address.
  2. For Type, select Interface.
  3. For Interface, select Interface: WWAN_Public.
7. Click the  to add another route policy.
8. For Label, enter Route through private APN.
9. For Interface, select Interface: WWAN_Private.
10. Configure the source address:
  1. Click to expand Source address.
  2. For Type, select Interface.
  3. For Interface, select LAN2.
11. Configure the destination address:
  1. Click to expand Destination address.
  2. For Type, select Interface.
  3. For Interface, select Interface: WWAN_Private.
Click Apply to save the configuration and apply the change.

 Command line

Select the device in Remote Manager and click Actions > Open Console, or log into the EX12 local command line as a user with full Admin access rights.
Depending on your device configuration, you may be presented with an Access selection menu. Type admin to access the Admin CLI.
At the command line, type config to enter configuration mode:
```
> config
(config)>
```

Set the maximum number of interfaces for the modem:

(config)> network modem modem max_intfs 2
(config)>

Create the WWAN interfaces:

Create the WWANPublic interface:

(config)> add network interface WWANPublic
(config network interface WWANPublic)>

Set the interface type to modem:

(config network interface WWANPublic)> type modem
(config network interface WWANPublic)>

Set the modem device:

(config network interface WWANPublic)> modem device modem
(config network interface WWANPublic)>

Configure whether you want the device to use the preconfigured APNs, custom APNs, or both. For more information, see Cellular modem APNs.
```
(config network interface WWANPublic)> modem apn public_apn
(config network interface WWANPublic)>
```

Use to periods (..) to move back one level in the configuration:

(config network interface WWANPublic)> ..
(config network interface)>

Create the WWANPrivate interface:

(config network interface)> add WWANPrivate
(config network interface WWANPrivate)>

Set the interface type to modem:

(config network interface WWANPrivate)> type modem
(config network interface WWANPrivate)>

Set the modem device:

(config network interface WWANPrivate)> modem device modem
(config network interface WWANPrivate)>

Enable APN list only:

(config network interface WWANPrivate)> modem apn_selection apn_list_only
(config network interface WWANPrivate)>

Set the private APN:

(config network interface WWANPublic)> modem apn private_apn
(config network interface WWANPublic)>

Create the routing policies. For example, to route all traffic from LAN1 through the public APN, and LAN2 through the private APN:

Add a new routing policy:

(config)> add network route policy end
(config network route policy 0)>

Set the label that will be used to identify this route policy:

(config network route policy 0)> label "Route through public apn"
(config network route policy 0)>

Set the interface:

(config network route policy 0)> interface /network/interface/WWANPublic
(config network route policy 0)>

Configure the source address:

Set the source type to interface:

(config network route policy 0)> src type interface
(config network route policy 0)>

Set the interface to LAN1:

(config network route policy 0)> src interface LAN1
(config network route policy 0)>

Configure the destination address:

Set the type to interface:

(config network route policy 0)> dst type interface
(config network route policy 0)>

Set the interface to WWANPublic :

(config network route policy 0)> interface /network/interface/WWANPublic
(config network route policy 0)>