To view bind version, run command

dig @NAME-SERVER-IP-HERE -c CH -t txt version.bind

It shows bind version

9.9.4-RedHat-9.9.4-51.el7

To hide bind version, edit named.conf

vi /etc/named.conf

You need to add

version "SOME-TEXT-HERE";

Inside your options block.

Now restart bind

systemctl restart named

Verify bind version changed with command

boby@hon-pc-01:~$ dig @hostonnet.com -c CH -t txt version.bind

; <<>> DiG 9.10.3-P4-Ubuntu <<>> @hostonnet.com -c CH -t txt version.bind
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18299
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;version.bind.			CH	TXT

;; ANSWER SECTION:
version.bind.		0	CH	TXT	"HostOnNet"

;; AUTHORITY SECTION:
version.bind.		0	CH	NS	version.bind.

;; Query time: 268 msec
;; SERVER: 158.69.114.170#53(158.69.114.170)
;; WHEN: Tue Nov 28 11:08:36 IST 2017
;; MSG SIZE  rcvd: 77

boby@hon-pc-01:~$