2.4.7.4. Connecting IP Gateways to the Internet or via External Providers 
The connection of IP gateways to the Internet or external providers
reveals a security vulnerability ("insecure" LAN/WAN). An IP or MAC address
filter must be set to combat this problem. This can be done via the board’s
WBM.
WBM > Configuration > Security > MAC Address Filtering
or WBM > Configuration > Security > IP Address Filtering.
For a detailed description, see "OpenScape 4000 V, Gateways HG 3500
and HG 3575, Administrator Documentation" ().