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Appendix D
Configuration Files
splitdns.config
The
splitdns.config
file enables you to specify the DNS server that Traffic server should use for resolving
hosts under specific conditions.
To specify a DNS server, you must supply the following information in each active line within the file:
•
A primary destination specifier in the form of a destination domain, a destination host, or a URL regular
expression
•
A set of server directives, listing one or more DNS servers with corresponding port numbers
You may also include the following optional information with each DNS server specification:
•
A default domain for resolving hosts
•
A search list specifying the domain search order when multiple domains are specified
For more information, refer to
Configuring DNS server selection (split DNS)‚ on page 91
.
Format
Each line in the
splitdns.config
file uses one of the following formats:
dest_domain=
dest_domain | dest_host | url_regex
named=”
dns_server
”
def_domain=”
def_domain
” search_list=”
search_list
”
The following table describes each field:
Example
Consider the following DNS server selection specifications:
dest_domain=internal.hp.com named=“255.255.255.255:212 255.255.255.254”
def_domain=“hp.com” search_list=“hp.com hp1.com”
dest_domain=!internal.hp.com named=“255.255.255.253”
Field
Allowed inputs
dest_domain
A valid domain name. This specifies that the DNS server selection be based on the
destination domain. You can prefix the domain with the “!” symbol to indicate the
NOT logical operator.
dest_host
A valid hostname. This specifies that the DNS server selection be based on the
destination host. You can prefix the host with the “!” symbol to indicate the NOT
logical operator.
url_regex
A valid URL regular expression. This specifies that the DNS server selection be based
on a regular expression.
dns_server
This is a required directive. It identifies the DNS server for Traffic Server to use with
the given destination specifier. You can specify a port using the “:” symbol; if you
don’t supply a port, 53 is used. You can specify multiple DNS servers separated by
spaces or the “;” symbol.
NOTE:
You must specify the domains using IP addresses in dot notation.
def_domain
A valid domain name. This optional directive specifies the default domain name to
use for resolving hosts. Only one entry is allowed. If you do not provide the default
domain, the system determines its value from /etc/resolv.conf.
search_list
A list of domains separated by spaces or “;”. This specifies the domain search order. If
you do not provide the search list, the system determines the value from /etc/
resolv.conf.