16

IP/MAC Binding

16.1 IP/MAC Binding Overview

IP address to MAC address binding helps ensure that only the intended devices get to use privileged IP addresses. The ZyWALL uses DHCP to assign IP addresses and records the MAC address it assigned to each IP address. The ZyWALL then checks incoming connection attempts against this list. A user cannot manually assign another IP to his computer and use it to connect to the ZyWALL.

Suppose you configure access privileges for IP address 192.168.1.27 and use static DHCP to assign it to Tim’s computer’s MAC address of 12:34:56:78:90:AB. IP/MAC binding drops traffic from any computer trying to use IP address 192.168.1.27 with another MAC address.

Figure 140 IP/MAC Binding Example

Bob

MAC: 12:34:56:78:90:AB

IP: 192.168.1.27

 

 

 

 

 

 

 

Jim

MAC: AB:CD:EF:12:34:56

 

IP: 192.168.1.27

16.1.1What You Can Do in this Chapter

•Use the Summary and Edit screens (Section 16.2 on page 242) to bind IP addresses to MAC addresses.

•Use the Exempt List screen (Section 16.3 on page 244) to configure ranges of IP addresses to which the ZyWALL does not apply IP/MAC binding.

16.1.2What You Need to Know

DHCP

IP/MAC address bindings are based on the ZyWALL’s dynamic and static DHCP entries.

 

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