To change LGW mode, navigate to the Network -> LGW page. In LGW L2 mode, the eNB will create a virtual interface for every UE that attaches. Each virtual interface will then do a DHCP request and create a 1:1 mapping between the UE IP (from Cloud EPC) and LGW IP. In L2 mode, the MAC address that the CPE uses is generated from the IMSI number. To calculate the CPE Mac address, convert the last 12 digits of the IMSI number to hex, then prefix it with 8A. For example, if the IMSI is 311980000002918, you would take the last 12 digits "980000002918" and convert it to hex which would equal "E42C8D5366", which brings us to the MAC address of 8A:E4:2C:8D:53:66. Once you know the MAC address, you can provision your networking accordingly.

Note:

About the LGW, the CPEs will get private IPs from the cloud EPC. Since the operator has no control over this, LGW is used to translate the IPs to match your own network. You can find some more details on this in the Nova LGW User Guide. We currently do not support VLANs using LGW. With LGW, your options are: NAT mode (L3 w/ NAT), where all CPEs will share the same IP address as the eNB, or Router mode (L3), where you can route to the LGW subnet.

To access the CPE remotely.
First, you have to do some settings on eNB and CPE before you can access into the CPE remotely.

From base station web GUI:
Under LTE Settings->LGW Settings, you can select either NAT (default) or Router mode. Under either mode, you can remotely access the CPE. Details of which are included in the attached LGW User Guide. Also, as described in this guide, you can statically assign an IP address to each CPE based on the SIM card’s IMSI number.

From CPE web GUI:
To enable remote access to the CPE, please remember to enable the “Allow HTTPS Login from WAN” parameter on the System->Web Setting page.