1-8
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Inspection of Basic Internet Protocols
DNS Inspection
Examples
The following example shows a how to define a DNS inspection policy map.
regex domain_example “example\.com”
regex domain_foo “foo\.com”
! define the domain names that the server serves
class-map type inspect regex match-any my_domains
match regex domain_example
match regex domain_foo
! Define a DNS map for query only
class-map type inspect dns match-all pub_server_map
match not header-flag QR
match question
match not domain-name regex class my_domains
policy-map type inspect dns new_dns_map
class pub_server_map
drop log
match header-flag RD
mask log
parameters
message-length maximum client auto
message-length maximum 512
dns-guard
protocol-enforcement
nat-rewrite
Configuring DNS Inspection
The default ASA configuration includes many default inspections on default ports applied globally on
all interfaces. A common method for customizing the inspection configuration is to customize the
default global policy. The steps in this section show how to edit the default global policy, but you can
alternatively create a new service policy as desired, for example, an interface-specific policy.
Detailed Steps
Command Purpose
Step 1
class-map name
Example:
hostname(config)# class-map dns_class_map
Creates a class map to identify the traffic for which you want to
apply the inspection.
In the default global policy, the inspection_default class map is a
special class map that includes default ports for all inspection
types (match default-inspection-traffic). If you are using this
class map in either the default policy or for a new service policy,
you can skip this step and the next step.
Step 2
match parameter
Example:
hostname(config-cmap)# match access-list
dns
Specifies the traffic in the class map. See the “Identifying Traffic
(Layer 3/4 Class Maps)” section on page 1-12 for more
information.
To Next Page
Loading...
Need help?
General