Cisco 7604 Configuration Guide - Page 373
Configuring ARP Inspection and Bridging Parameters, Configuring ARP Inspection
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19 C H A P T E R Configuring ARP Inspection and Bridging Parameters Transparent Firewall Mode Only This chapter describes how to enable ARP inspection and how to customize bridging operations for the FWSM. In multiple context mode, the commands in this chapter can be entered in a security context, but not the system. This chapter includes the following sections: • Configuring ARP Inspection, page 19-1 • Customizing the MAC Address Table, page 19-3 Configuring ARP Inspection This section describes ARP inspection and how to enable it, and includes the following topics: • ARP Inspection Overview, page 19-1 • Adding a Static ARP Entry, page 19-2 • Enabling ARP Inspection, page 19-2 ARP Inspection Overview By default, all ARP packets are allowed through the FWSM. You can control the flow of ARP packets by enabling ARP inspection. ARP inspection settings apply to all bridge groups. When you enable ARP inspection, the FWSM compares the MAC address, IP address, and source interface in all ARP packets to static entries in the ARP table, and takes the following actions: • If the IP address, MAC address, and source interface match an ARP entry, the packet is passed through. • If there is a mismatch between the MAC address, the IP address, or the interface, then the FWSM drops the packet. • If the ARP packet does not match any entries in the static ARP table, then you can set the FWSM to either forward the packet out all interfaces (flood), or to drop the packet. OL-20748-01 Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM 19-1
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