Cisco ASA 5505 Configuration Manual page 318

Configuring Regular Expressions
Guidelines and Limitations for Objects and Groups
This section includes the guidelines and limitations for this feature.
Context Mode Guidelines
Supported in single and multiple context mode.
Firewall Mode Guidelines
Supported in routed and transparent firewall modes.
IPv6 Guidelines
Supports IPv6, with limitations. (See the
Additional Guidelines and Limitations
The following guidelines and limitations apply to object groups:
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The adaptive security appliance does not support IPv6 nested object groups, so you cannot group an
object with IPv6 entities under another IPv6 object group.
Configuring Regular Expressions
A regular expression matches text strings either literally as an exact string, or by using metacharacters
so that you can match multiple variants of a text string. You can use a regular expression to match the
content of certain application traffic; for example, you can match a URL string inside an HTTP packet.
This section describes how to create a regular expression and includes the following topics:
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Creating a Regular Expression
A regular expression matches text strings either literally as an exact string, or by using metacharacters
so you can match multiple variants of a text string. You can use a regular expression to match the content
of certain application traffic; for example, you can match a URL string inside an HTTP packet.
Cisco ASA 5500 Series Configuration Guide using ASDM
13-10
Objects and object groups share the same name space.
Object groups must have unique names. While you might want to create a network object group
named "Engineering" and a service object group named "Engineering," you need to add an identifier
(or "tag") to the end of at least one object group name to make it unique. For example, you can use
the names "Engineering_admins" and "Engineering_hosts" to make the object group names unique
and to aid in identification.
You cannot remove an object group or make an object group empty if it is used in a command.
Creating a Regular Expression, page 13-10
Building a Regular Expression, page 13-13
Testing a Regular Expression, page 13-14
Creating a Regular Expression Class Map, page 13-15
Additional Guidelines and Limitations, page
Chapter 13 Configuring Objects
13-10. )
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