Você pode ocultar hostname e versão desta forma:
# /etc/named.conf
options {
// hide bind info
hostname "unknown";
version "unknown";
}
Exemplo de consulta do nome do host:
[vitalie@silver ~]$ dig @ns1.kappa.ro hostname.bind chaos txt
; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_5.3 <<>> @ns1.kappa.ro hostname.bind chaos txt
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46430
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;hostname.bind. CH TXT
;; ANSWER SECTION:
hostname.bind. 0 CH TXT "linux.kappa.ro"
;; AUTHORITY SECTION:
hostname.bind. 0 CH NS hostname.bind.
;; Query time: 6 msec
;; SERVER: 194.102.255.3#53(194.102.255.3)
;; WHEN: Wed Jan 5 15:08:14 2011
;; MSG SIZE rcvd: 72