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Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring the Botnet Traffic Filter
Configuring the Botnet Traffic Filter
Default DNS Inspection Configuration and Recommended Configuration
The default configuration for DNS inspection inspects all UDP DNS traffic on all interfaces, and does
not have DNS snooping enabled.
We suggest that you enable DNS snooping only on interfaces where external DNS requests are going.
Enabling DNS snooping on all UDP DNS traffic, including that going to an internal DNS server, creates
unnecessary load on the ASA.
For example, if the DNS server is on the outside interface, you should enable DNS inspection with
snooping for all UDP DNS traffic on the outside interface. See the
section for the
recommended commands for this configuration.
Detailed Steps
Command
Purpose
Step 1
class-map
name
Example:
hostname(config)# class-map
dynamic-filter_snoop_class
Creates a class map to identify the traffic for which you want to
inspect DNS.
Step 2
match
parameters
Example:
hostname(config-cmap)# match port udp eq
domain
Specifies traffic for the class map. See the
“Identifying Traffic
(Layer 3/4 Class Maps)” section on page 35-12
for more
information about available parameters. For example, you can
specify an access list for DNS traffic to and from certain
addresses, or you can specify all UDP DNS traffic.
Step 3
policy-map
name
Example:
hostname(config)# policy-map
dynamic-filter_snoop_policy
Adds or edits a policy map so you can set the actions to take with
the class map traffic.
Step 4
class
name
Example:
hostname(config-pmap)# class
dynamic-filter_snoop_class
Identifies the class map you created in
.
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: ......