1-12
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Inspection of Basic Internet Protocols
FTP Inspection
Configuring an FTP Inspection Policy Map for Additional Inspection
Control
FTP command filtering and security checks are provided using strict FTP inspection for improved
security and control. Protocol conformance includes packet length checks, delimiters and packet format
checks, command terminator checks, and command validation.
Blocking FTP based on user values is also supported so that it is possible for FTP sites to post files for
download, but restrict access to certain users. You can block FTP connections based on file type, server
name, and other attributes. System message logs are generated if an FTP connection is denied after
inspection.
If you want FTP inspection to allow FTP servers to reveal their system type to FTP clients, and limit the
allowed FTP commands, then create and configure an FTP map. You can then apply the FTP map when
you enable FTP inspection.
To create an FTP map, perform the following steps:
Step 1
(Optional) Add one or more regular expressions for use in traffic matching commands according to the
“Creating a Regular Expression” section on page 1-14
. See the types of text you can match in the
match
.
Step 2
(Optional) Create one or more regular expression class maps to group regular expressions according to
the
“Creating a Regular Expression Class Map” section on page 1-17
Step 3
(Optional) Create an FTP inspection class map by performing the following steps.
A class map groups multiple traffic matches. Traffic must match
all
of the
match
commands to match
the class map. You can alternatively identify
match
commands directly in the policy map. The difference
between creating a class map and defining the traffic match directly in the inspection policy map is that
the class map lets you create more complex match criteria, and you can reuse class maps.
To specify traffic that should not match the class map, use the
match not
command. For example, if the
match not
command specifies the string “example.com,” then any traffic that includes “example.com”
does not match the class map.
For the traffic that you identify in this class map, you can specify actions such as drop, drop-connection,
reset, mask, set the rate limit, and/or log the connection in the inspection policy map.
If you want to perform different actions for each
match
command, you should identify the traffic directly
in the policy map.
a.
Create the class map by entering the following command:
hostname(config)#
class-map type
inspect
ftp
[
match-all
|
match-any
]
class_map_name
hostname(config-cmap)#
Where
class_map_name
is the name of the class map. The
match-all
keyword is the default, and
specifies that traffic must match all criteria to match the class map. The
match-any
keyword
specifies that the traffic matches the class map if it matches at least one of the criteria. The CLI
enters class-map configuration mode, where you can enter one or more
match
commands.
b.
(Optional) To add a description to the class map, enter the following command:
hostname(config-cmap)#
description
string
c.
(Optional) To match a filename for FTP transfer, enter the following command:
hostname(config-cmap)#
match
[
not
]
filename regex
[
regex_name
|
class
regex_class_name
]
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: ......