Cisco Systems Configuring Application Layer Protocol Inspection

9-7
Cisco ASA Series Firewall CLI Configuration Guide
Chapter9 Getting Started with Application Layer Protocol Inspection
Configuring Application Layer Protocol Inspection
class-map inspection_default
match default-inspection-traffic
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
dns-guard
protocol-enforcement
nat-rewrite
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect ftp
inspect h323 h225 _default_h323_map
inspect h323 ras _default_h323_map
inspect ip-options _default_ip_options_map
inspect netbios
inspect rsh
inspect rtsp
inspect skinny
inspect esmtp _default_esmtp_map
inspect sqlnet
inspect sunrpc
inspect tftp
inspect sip
inspect xdmcp
Configuring Application Layer Protocol Inspection
This feature uses Modular Policy Framework to create a service policy. Service policies provide a
consistent and flexible way to configure ASA features. For example, you can use a service policy to
create a timeout configuration that is specific to a particular TCP application, as opposed to one that
applies to all TCP applications. See Chapter1, “Configuring a Service Policy Using the Modular Policy
Framework,” for more information. For some applications, you can perform special actions when you
enable inspection. See Chapter 1, “Configuring a Service Policy Using the Modular Policy Framework,”
for more information.
Inspection is enabled by default for some applications. See the “Default Settings and NAT Limitations”
section for more information. Use this section to modify your inspection policy.
Detailed Steps
Step1 To identify the traffic to which you want to apply inspections, add either a Layer 3/4 class map for
through traffic or a Layer 3/4 class map for management traffic. See the “Creating a Layer 3/4 Class Map
for Through Traffic” section on page1-12 and “Creating a Layer 3/4 Class Map for Management
Traffic” section on page1-14 for detailed information. The management Layer 3/4 class map can be used
only with the RADIUS accounting inspection.
The default Layer 3/4 class map for through traffic is called “inspection_default.” It matches traffic using
a special match command, match default-inspection-traffic, to match the default ports for each
application protocol. This traffic class (along with match any, which is not typically used for inspection)
matches both IPv4 and IPv6 traffic for inspections that support IPv6. See the “Guidelines and
Limitations” section on page9-3 for a list of IPv6-enabled inspections.