User manual

ADTRAN Routers with CradlePoint CBA750B Configuring the CradlePoint CBA750B

Step 8: Enable the Force 24 Subnet Option

The CradlePoint CBA750B must be configured with the Force 24 subnet option for reliable operation with

Verizon and other wireless 3G/4G LTE service providers. Verizon uses GGSN to assign wireless user IP

addresses. These addresses may fall on a subnet boundary and cause routing issues. To avoid these issues,

the Force 24 option must be enabled.

When using the Force 24 option, the CBA750B's DHCP server will assign the gateway IP address of

xxx.xxx.xxx.1 in the /24 subnet for the LAN interface that connects to the ADTRAN router.

To configure Force 24 option, follow these steps:

1. From the CBA750B web interface, use the Network Settings drop-down menu to select Local

Networks. The Local Networks menu will appear.

2. In the Local IP Networks section of the Local Networks menu, select the check box next to Primary

LAN. Then, select the Edit button. The Local Network Editor will appear.

3. In the Local Network Editor, select the IPv4 Settings tab.