Using the GeoIP Features in BIND 9.10

AA-01149

BIND 9 access control lists are used to limit access to various server functions according to the IP address of the requestor of that access.  BIND 9.10 is able to use data from MaxMind GeoIP databases to achieve restrictions based on the (presumed) geographic location of that address. The ACL itself is still address-based, but the GeoIP-based specification mechanisms can easily populate an ACL with addresses in a certain geographic location. This capability was derived from code contributed by Ken Brownfield. An interesting use of geographic ACLs is to offer different BIND Views to clients in different geographic locations.

BIND 9.10's GeoIP features work by allowing you to create ACL elements that evaluate based on the location information for the client's IP address.  This uses the API provided by MaxMind® to query their GeoIP database but should work with any database in a compatible format.

The primary intended purpose for the GeoIP feature is to permit the creation of answer sets specific to geographic regions, in order to connect clients with local services.  This can result in improved response time for the client and a reduction in long-haul network traffic.

In order to use the GeoIP features, BIND must be built with GeoIP support by using '--with-geoip' in the configure step of the build process .  Without this build configuration BIND will not recognize the named.conf GeoIP extensions or be able to perform any GeoIP lookups.

When built with GeoIP, named.conf supports the "geoip-directory" option.

options {
    geoip-directory "/path/to/geoip/database";
};
ACLs can  perform GeoIP lookup tests using the client IP address.  Many different types of GeoIP lookups can be performed.  For more detailed information about what is supported see chapter 6 of the ARM that came with your BIND distribution.

acl "example" {
  geoip country US;
  geoip region CA;
  geoip city "Redwood City"; /* names, etc., must be quoted if they contain spaces */
};

While these can be used in any ACLs, the most common place to use them is in the match statements on views in order to route clients to the view with the answers selected for their location.

options {
    geoip-directory "/path/to/geoip/database";
};

acl "redwoodcity" {
  geoip country US;
  geoip region CA;
  geoip city "Redwood City"; /* names, etc., must be quoted if they contain spaces */
};

view "redwoodcity" {
  match-clients { redwoodcity; };
  zone "isc.org" {
    file "locals/db.isc.org";
    type master;
  };
};

view "default" {
  zone "isc.org" {
    file "nonlocals/db.isc.org";
    type master;
  };
};