[BIND] DNS update denied

drop any $EXTERNAL_NET any -> $HOME_NET any (msg: "[BIND] DNS update denied"; pcre: "/denied update from
| unapproved update from/"; default_proto: udp; default_dst_port: $DNS_PORT; classtype: attempted-recon; xbits: set,recon,track ip_src, expire 86400; program: named; parse_port; parse_src_ip: 1; sid:5000103; rev:9;)