root@server:~# apt-get install bind9

root@server:~# cat /etc/bind/named.conf

options {
        directory "/var/cache/bind";

        allow-recursion { any; };
        
        forwarders {
                172.16.1.254;
        };
};

view "inside" {
        match-clients {
//            192.168.X/24;
//            127/8;
              0/0;
        };
        zone "corpX.un" {
                type master;
                file "/var/cache/bind/corpX.un";
        };

        zone "X.168.192.IN-ADDR.ARPA" {
                type master;
                file "/var/cache/bind/corpX.rev";
        };
};

view "outside" {
        zone "corpX.un" {
                type master;
                file "/var/cache/bind/corpX.un.out";
        };
};

root@server:~# cd /var/cache/bind/

[server:~] # cat /etc/namedb/named.conf

options {
        directory       "/etc/namedb";
        pid-file        "/var/run/named/pid";

        allow-recursion { any; };
        
        forwarders {
                172.16.1.254;
        };
};

view "inside" {
        match-clients {
//              192.168.X/24;
//              127/8;
                0/0;
        };
        zone "corpX.un" {
                type master;
                file "master/corpX.un";
        };

        zone "X.168.192.IN-ADDR.ARPA" {
                type master;
                file "master/corpX.rev";
        };
};
view "outside" {
        zone "corpX.un" {
                type master;
                file "master/corpX.un.out";
        };
};

[server:~] # cd /etc/namedb/master/

server# cat corpX.un

$TTL      3h
@         SOA     ns root.ns  1 1d 12h 1w 3h
          NS      ns

;ns        A       192.168.X.10
;gate      A       192.168.X.1
;server    A       192.168.X.10
;lan       A       192.168.100+X.10

;ftp      CNAME   server
;www      CNAME   server
;nfs      CNAME   server
;mail     CNAME   server
;ntp	  CNAME   gate

;router    A       192.168.X.1
;switch    A       192.168.X.3

;ns        A       192.168.X.1
;ns        A       192.168.X.2
;node1     A       192.168.X.1
;node2     A       192.168.X.2
;gate      A       192.168.X.254

;_sip._udp           SRV     00 00 5060 server

;_kerberos._udp      SRV     01 00 88 server
;_kerberos._tcp      SRV     01 00 88 server
;_kerberos           TXT     CORPX.UN

server# cat corpX.rev

$TTL    3h
@       SOA     ns.corpX.un. root.ns.corpX.un.  1 1d 12h 1w 3h
        NS      ns.corpX.un.
       
 
;10      PTR     server.corpX.un.
;1       PTR     gate.corpX.un.

;1       PTR     router.corpX.un.
;3       PTR     switch.corpX.un.

;1       PTR     node1.corpX.un.
;2       PTR     node2.corpX.un.
;254     PTR     gate.corpX.un.

server# cat corpX.un.out

$TTL      3h
@         SOA     ns root.ns  1 1d 12h 1w 3h
          NS      ns

ns        A       172.16.1.X

;gate      A       172.16.1.X
;server    A       172.16.1.X

;ftp      CNAME   server
;www      CNAME   server
;mail     CNAME   server

;_sip._udp           SRV     00 00 5060 server

server# named-checkconf -z

[server:~] # cat /etc/rc.conf

...
named_enable="YES"

[server:~] # /etc/rc.d/named start

root@server:~# /etc/init.d/bind9 restart

server# cat /etc/resolv.conf

domain corpX.un
nameserver 127.0.0.1

gate# cat /etc/resolv.conf

domain corpX.un
nameserver 192.168.X.10

lan# cat /etc/resolv.conf

domain corpX.un
nameserver 192.168.X.10

# host ya.ru
# host gate.corpX.un
# host server.corpX.un
# host 192.168.X.10
# host 192.168.X.1

ns.isp.un# cat named.conf

...
zone "un" {
        type master;
        file "un";
};
...
zone "corp1.un" IN {type forward;forwarders {192.168.1.10;};};
...
zone "corp12.un" IN {type forward;forwarders {192.168.12.10;};};

//zone "corp1.un" IN {type forward;forwarders {172.16.1.1;};};
...
//zone "corp12.un" IN {type forward;forwarders {172.16.1.12;};};
...

gate.isp.un# cat un

...
ns1            A       192.168.1.10
...
ns12           A       192.168.12.10

;ns1           A       172.16.1.1
...
;ns12          A       172.16.1.12
...
corp1          NS      ns1
...
corp12         NS      ns12
...