By setting the MAC address filtering, you can allow only your own device to access the network (whitelist), or do not allow unauthorized devices to access the network (blacklist), effectively preventing unauthorized network access.
Huawei ONTs support the MAC address filtering for wired and wireless networks. The following describes the two scenarios, respectively.
MAC address filtering on wired networks
1. Click the Advanced Configuration > Security Configuration tab and choose MAC Address Filtering in the navigation tree on the left. In the pane on the right, after enabling the MAC filter and selecting the filter mode, click New. On the dialog box that is displayed, configure the MAC filter rule for the PC to access the Internet.

2. Click Apply.
The MAC address lists of the PCs in the network are saved on the ONT. Configuring the MAC filter rules enables the PCs that abide to the rules to access the Internet service or disables the PCs that do not abide to the rules to access the Internet service.
A PC may have more than one IP address, but a unique MAC address. Therefore, configuring the MAC filter rules effectively controls the Internet service access rights of the PCs in a LAN.
The parameters related to the MAC address filter:

MAC address filtering on wireless networks
1. Click the Security tab, and choose WLAN MAC Filter Configuration from the navigation tree on the left. On the right pane, select Enable WAN MAC filter, set the filter mode and click New. In the dialog box that is displayed, configure the SSID-based MAC address filter rule.

2. Click Apply.
The parameters for wireless network MAC filtering:

https://forum.huawei.com/enterprise/en/how-to-configure-the-mac-address-filtering-to-prevent-unauthorized-network-access-on-a-huawei-ont-q-a/thread/461925-100181