How to Define Remote Host Name Patterns Using Regular Expressions

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How to Define Remote Host Name Patterns Using Regular Expressions

When you configure host groups, you specify host name patterns and IP address patterns or both. Regular expression operators that you can apply when defining Remote Host Patterns for Host Groups follow:

^ (caret) means starts with.
\ (escape) means interpret the operator character that immediately follows as a literal.
. (dot) within an expression means any character. The expression a.b matches any string of three characters starting with “a” and ending with “b”.
.* (dot asterisk) means accept any character any number of times. The expression a.*b matches a string of any length starting with "a" and ending with "b".
$ (dollar sign) means ends with.

Think of the regular expression as a way to express anything in the FQDN, including:

a start pattern (^String)
a middle pattern (String)
an end pattern (String$)
a precise pattern (^StringWithEscapedDots$)

The following table contains examples designed to help you enter host name patterns in a way that helps ensure efficient processing. If you enter an FQDN or subdomain without operators, the FQDN or group you intend to map is found, but processing is not as efficient. As a best practice, include the following regular expression combinations in the host name patterns you enter for Remote Host Patterns.

Common Combinations	Description	Example FQDN and Example Host Group
^<hostname>	The caret as the first character means that the pattern starts with the text that follows the caret.	FQDN: ^host1\.ca\.com$ matches only host1.ca.com (But, host1\.ca\.com$ without the preceding caret searches for every host with a name that ends with host1.ca.com, such as aaaahost1.ca.com) Group: ca\.com$ without the preceding caret matches every FQDN in the ca.com subdomain.
\.	The escape dot combination (\.) means to interpret the dot as a literal.	FQDN: ^host1\.ca\.com$ matches only host1.ca.com (But, ^host.ca.com$ without an escape before each dot could match: host1Mca0com) Group: ^host.\.ca\.com$ with a dot after host could match hosts named {host0, host1, ...hostZ} in the ca.com domain.
.*<domain>	The dot asterisk combination (.*) allows everything to match.	Group: .\.ca\.com$, a domain preceded by . matches all hosts in the Domain.
<domain name>$	The dollar sign following a domain name means that the pattern ends with the specified domain.	FQDN: ^host1\.ca\.com$ matches only host1.ca.com (But ^host1\.ca\.com without the ending $ operator could match: host1.ca.comaaaaaaa)

Examples

Remote IP Address Patterns

Specifies any combination of the following, where IP addresses are static rather than dynamic. Click Add to create each row.

A list of IPv4 IP addresses.
One or more IPv4 subnets using CIDR notation.

Remote Host Name Patterns

Specifies a group of remote hosts with a list of fully qualified domain names (FQDN) or regular expression patterns for a subdomain. Select Add to create a row for each pattern entry.

For example:

abc\.mycompany\.com
.*pam-lnx\.mycompany\.com$
This pattern matches any hostname that ends in pam-lnx in your company domain, where mycompany is replaced with your company name.
^machine1\.mycompany\.com$
Specifically, ^machine1\.mycompany\.com$ expresses a Fully Qualified Domain Name (FQDN) as a regular expression. This pattern matches only the FQDN that meets all of these criteria:

starts with machine1.

ends with com.

contains machine1, then a dot, then mycompany, then a dot, and then com.