CHAPT ER
46-1
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
46
Configuring Dynamic ARP Inspection
This chapter describes how to configure Dynamic ARP Inspection (DAI) on the Catalyst 4500 series
switch.
This chapter includes the following major sections:
About Dynamic ARP Inspection, page 46-1
Configuring Dynamic ARP Inspection, page 46-5
Note For complete syntax and usage information for the switch commands used in this chapter, first look at
the Cisco Catalyst 4500 Series Switch Command Reference and related publications at this location:
http://www.cisco.com/en/US/products//hw/switches/ps4324/index.html
If the command is not found in the Catalyst 4500 Command Reference, it will be found in the larger
Cisco IOS library. Refer to the Cisco IOS Command Reference and related publications at this location:
http://www.cisco.com/en/US/products/ps6350/index.html

About Dynamic ARP Inspection

Dynamic ARP Inspection (DAI) is a security feature that validates Address Resolution Protocol (ARP)
packets in a network. DAI allows a network administrator to intercept, log, and discard ARP packets with
invalid MAC-IP pairs. This capability protects the network from certain “man-in-the-middle” attacks.
This section contains the following subsections:
ARP Cache Poisoning, page 46-2
Purpose of Dynamic ARP Inspection, page 46-2
Interface Trust State, Security Coverage and Network Configuration, page 46-3
Relative Priority of Static Bindings and DHCP Snooping Entries, page 46-4
Logging of Dropped Packets, page 46-4
Rate Limiting of ARP Packets, page 46-4
Port Channels Function, page 46-5