options { directory "/var/cache/bind"; dnssec-validation auto; listen-on-v6 { any; }; allow-query { any; }; max-cache-size 30%; querylog yes; % if type == 'master': notify yes; also-notify { ${' '.join([f'{ip};' for ip in slave_ips])} }; allow-transfer { ${' '.join([f'{ip};' for ip in slave_ips])} }; % endif };