Fortinet FortiGate 50A User Manual

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Fortinet Inc.

IP/MAC binding

Firewall configuration

Select New to add IP/MAC binding pairs to the IP/MAC binding list.

All packets that would normally be allowed through the firewall by a firewall policy are
first compared with the entries in the IP/MAC binding list. If a match is found, then the
firewall attempts to match the packet with a policy.

For example, if the IP/MAC pair IP 1.1.1.1 and 12:34:56:78:90:ab:cd is added to the
IP/MAC binding list:

• A packet with IP address 1.1.1.1 and MAC address 12:34:56:78:90:ab:cd is

allowed to go on to be matched with a firewall policy.

• A packet with IP 1.1.1.1 but with a different MAC address is dropped immediately

to prevent IP spoofing.

• A packet with a different IP address but with a MAC address of

12:34:56:78:90:ab:cd is dropped immediately to prevent IP spoofing.

• A packet with both the IP address and MAC address not defined in the IP/MAC

binding table:
• is allowed to go on to be matched with a firewall policy if IP/MAC binding is set

to Allow traffic,

• is blocked if IP/MAC binding is set to Block traffic.

Configuring IP/MAC binding for packets going to the firewall

Use the following procedure to use IP/MAC binding to filter packets that would
normally connect with the firewall (for example, when an administrator is connecting to
the FortiGate unit for management).

To configure IP/MAC binding for packets going to the firewall

Go to Firewall > IP/MAC Binding > Setting.

Select the Enable IP/MAC binding going to the firewall check box.

Go to Firewall > IP/MAC Binding > Static IP/MAC.