BIND 9.10 and later: use the "in-view" zone option to allow both views to use the same in-memory instance of the zone. See the ARM for your version of BIND for more details.
BIND 9.9 and later: see examples 3 and 4 of Understanding views in BIND 9, by example for an alternate method.
BIND 9.3 and later: Use TSIG to select the appropriate view.
Note the key must be specified before the address in the match-clients acls as processing of the ACL stops on first match.
Primary 10.0.1.1:
key "external" {
algorithm hmac-md5;
secret "xxxxxxxx";
};
view "internal" {
match-clients { !key external; 10.0.1/24; };
...
};
view "external" {
match-clients { key external; any; };
server 10.0.1.2 { keys external; };
recursion no;
...
};
Secondary 10.0.1.2:
key "external" {
algorithm hmac-md5;
secret "xxxxxxxx";
};
view "internal" {
match-clients { !key external; 10.0.1/24; };
...
};
view "external" {
match-clients { key external; any; };
server 10.0.1.1 { keys external; };
recursion no;
...
};