The Arp Inspection Screen; Configuring Arp Inspection - ZyXEL Communications MES-2110 User Manual

19.4 The ARP Inspection Screen

Use ARP inspection to filter unauthorized ARP frames on the network. This can
prevent many kinds of man-in-the-middle attacks, such as the one in the following
example.
Figure 68 Example: Man-in-the-middle Attack
A
In this example, computer B tries to establish a connection with computer A.
Computer X is in the same broadcast domain as computer A and intercepts the
ARP request for computer A. Then, computer X does the following things:
• It pretends to be computer A and responds to computer B.
• It pretends to be computer B and sends a message to computer A.
As a result, all the communication between computer A and computer B passes
through computer X. Computer X can read and alter the information passed
between them.

19.4.1 Configuring ARP Inspection

Follow these steps to configure ARP inspection on the MES-2110.
Configure DHCP snooping. See
1
Note: It is recommended you enable DHCP snooping at least one day before you
enable ARP inspection so that the MES-2110 has enough time to build the
binding table.
Enable ARP inspection on the MES-2110. See
2
details about turning on this feature.
MES-2110 User's Guide
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Section 19.1.1.3 on page
Section 19.4 on page 147
Chapter 19 IP Source Guard
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142.
for more
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