NAME

       splitdns.config - Traffic Server split DNS configuration file

       The  splitdns.config file enables you to specify the DNS server that Traffic Server should
       use for resolving hosts under specific conditions.  For more information, refer  to  Split
       DNS.

       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  can  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

       After  you  modify  the splitdns.config file, run the traffic_ctl config reload command to
       apply the changes.

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 list describes each field.

       dest_domain
              A valid domain name. This specifies that DNS server selection will be based on  the
              destination  domain.  You  can  prefix  the  domain with an exclamation mark (!) to
              indicate the NOT logical operator.

       dest_host
              A valid hostname. This specifies that DNS server selection will  be  based  on  the
              destination  host. You can prefix the host with an exclamation mark (!) to indicate
              the NOT logical operator.

       url_regex
              A valid URL regular expression. This specifies that DNS server  selection  will  be
              based on a regular expression.

       named  This  is  a  required  directive.  It identifies the DNS server that Traffic Server
              should use with the given destination specifier. You can specify  a  port  using  a
              colon  (:).  If  you  do  not specify a port, then 53 is used. Specify multiple DNS
              servers with spaces or semicolons (;) as separators.

              You must specify the domains with IP addresses in CIDR ("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 semicolons (;). This specifies the  domain
              search  order.  If  you  do  not provide the search list, the system determines the
              value from resolv.conf(5)

EXAMPLES

       Consider the following DNS server selection specifications:

          dest_domain=internal.company.com named="255.255.255.255:212 255.255.255.254" def_domain=company.com search_list="company.com company1.com"
          dest_domain=!internal.company.com named=255.255.255.253

       Now consider the following two requests:

          http://minstar.internal.company.com

       This request matches the first line and therefore selects DNS  server  255.255.255.255  on
       port 212. All resolver requests use company.com as the default domain, and company.com and
       company1.com as the set of domains to search first.

          http://www.microsoft.com

       This request matches the  second  line.  Therefore,  Traffic  Server  selects  DNS  server
       255.255.255.253.  Because  no  def_domain  or  search_list  was  supplied,  Traffic Server
       retrieves this information from resolv.conf(5)

COPYRIGHT

       2023, dev@trafficserver.apache.org