1-10
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring the Transparent or Routed Firewall
Configuring ARP Inspection for the Transparent Firewall
Detailed Steps
Configuring ARP Inspection for the Transparent Firewall
This section describes how to configure ARP inspection and includes the following topics:
•
Task Flow for Configuring ARP Inspection, page 1-10
•
Adding a Static ARP Entry, page 1-10
•
Enabling ARP Inspection, page 1-11
Task Flow for Configuring ARP Inspection
To configure ARP Inspection, perform the following steps:
Step 1
Add static ARP entries according to the
“Adding a Static ARP Entry” section on page 1-10
. ARP
inspection compares ARP packets with static ARP entries in the ARP table, so static ARP entries are
required for this feature.
Step 2
Enable ARP inspection according to the
“Enabling ARP Inspection” section on page 1-11
Adding a Static ARP Entry
ARP inspection compares ARP packets with static ARP entries in the ARP table. Although hosts identify
a packet destination by an IP address, the actual delivery of the packet on Ethernet relies on the Ethernet
MAC address. When a router or host wants to deliver a packet on a directly connected network, it sends
an ARP request asking for the MAC address associated with the IP address, and then delivers the packet
to the MAC address according to the ARP response. The host or router keeps an ARP table so it does not
have to send ARP requests for every packet it needs to deliver. The ARP table is dynamically updated
whenever ARP responses are sent on the network, and if an entry is not used for a period of time, it times
out. If an entry is incorrect (for example, the MAC address changes for a given IP address), the entry
times out before it can be updated.
Note
The transparent firewall uses dynamic ARP entries in the ARP table for traffic to and from the ASA,
such as management traffic.
Command
Purpose
firewall transparent
Example:
hostname(config)# firewall transparent
Sets the firewall mode to transparent. To change the mode to routed, enter
the
no firewall transparent
command.
Note
You are not prompted to confirm the firewall mode change; the
change occurs immediately.
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......