Ip/Mac Binding; Configuring Ip/Mac Binding For Packets Going Through The Firewall - Fortinet FortiGate 50A Installation And Configuration Manual

Firewall configuration

IP/MAC binding

Configuring IP/MAC binding for packets going through the firewall

FortiGate-50A Installation and Configuration Guide
If you want connections to originate from all your Internet IP addresses, you can add
this address range to an IP pool for the external interface. Then you can select
Dynamic IP Pool for all policies with the external interface as the destination. For each
connection, the firewall dynamically selects an IP address from the IP pool to be the
source address for the connection. As a result, connections to the Internet appear to
be originating from any of the IP addresses in the IP pool.
IP/MAC binding protects the FortiGate unit and your network from IP spoofing attacks.
IP spoofing attacks try to use the IP address of a trusted computer to connect to, or
through, the FortiGate unit from a different computer. The IP address of a computer is
easy to change to a trusted address, but MAC addresses are added to ethernet cards
at the factory and are not easy to change.
You can enter the static IP addresses and corresponding MAC addresses of trusted
computers in the static IP/MAC table.
If you have trusted computers with dynamic IP addresses that are set by the FortiGate
DHCP server, the FortiGate unit adds these IP addresses and their corresponding
MAC addresses to the dynamic IP/MAC table. For information about viewing the table,
see "Viewing a DHCP server dynamic IP list" on page
binding table is not available in Transparent mode.
You can enable IP/MAC binding for packets in sessions connecting to the firewall or
passing through the firewall.
Note: If you enable IP/MAC binding and change the IP address of a computer with an IP or
MAC address in the IP/MAC list, you must also change the entry in the IP/MAC list or the
computer does not have access to or through the FortiGate unit. You must also add the IP/MAC
address pair of any new computer that you add to your network or the new computer does not
have access to or through the FortiGate unit.
This section describes:
• Configuring IP/MAC binding for packets going through the firewall
• Configuring IP/MAC binding for packets going to the firewall
• Adding IP/MAC addresses
• Viewing the dynamic IP/MAC list
• Enabling IP/MAC binding
Use the following procedure to use IP/MAC binding to filter packets that a firewall
policy would normally allow through the firewall.
To configure IP/MAC binding for packets going through the firewall
1 Go to Firewall > IP/MAC Binding > Setting.
2 Select the Enable IP/MAC binding going through the firewall check box.
3 Go to Firewall > IP/MAC Binding > Static IP/MAC.
IP/MAC binding
107. The dynamic IP/MAC
163