bionic (5) splitdns.config.5.gz

Provided by: trafficserver_7.1.2+ds-3_amd64 bug

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 admin-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. When you apply changes to a node in a cluster, Traffic Server automatically applies the  changes
       to all other nodes in the cluster.

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)

       2018, dev@trafficserver.apache.org