DNS - exemples de fichiers de config réseau local

l'idée c'est qu'on veut configurer un chtit caching name server sur un réseau local.
Donc on commence par installer bind9,puis en avant la configuration
Dans le fichier named.conf

include "/etc/bind/named.conf.options";

// prime the server with knowledge of the root servers

zone "." {

        type hint;

        file "/etc/bind/db.root";

};

// be authoritative for the localhost forward and reverse zones, and for

// broadcast zones as per RFC 1912

zone "localhost" {

        type master;

        file "/etc/bind/db.local";

};

zone "127.in-addr.arpa" {

        type master;

        file "/etc/bind/db.127";

};

zone "0.in-addr.arpa" {

        type master;

        file "/etc/bind/db.0";

};

zone "255.in-addr.arpa" {

        type master;

        file "/etc/bind/db.255";

};

zone "com" { type delegation-only; };

zone "net" { type delegation-only; };



include "/etc/bind/named.conf.local";

puis à la fin de named.conf est inclu le contenu de named.conf.local

zone "labo.org" {

        type master;

        file "/etc/bind/db.labo.org";

};



zone "10.in-addr.arpa" {

        type master;

        file "/etc/bind/db.10.in-addr.arpa";

};

maintenant db.labo.org

$TTL    1H

@       IN      SOA     ns1.labo.org. root.labo.org. (

                     2004071402         ; Serial

                             1H         ; Refresh

                             1H         ; Retry

                             1H         ; Expire

                             1D )       ; Negative Cache TTL

;

@       IN      NS      ns1.labo.org.



ns1     IN      A       10.0.0.4

box3    IN      A       10.0.0.3

fw1     IN      A       10.0.0.1

fw2     IN      A       10.0.0.2

et dans db.10.in-addr.arpa

$TTL    1H

@       IN      SOA     ns1.labo.org. root.labo.org. (

                     2004071402         ; Serial

                             1H         ; Refresh

                             1H         ; Retry

                             1H         ; Expire

                             1D )       ; Negative Cache TTL



@       IN      NS      ns1.labo.org.



4.0.0.10.in-addr.arpa.  IN      PTR     ns1.labo.org.

3.0.0.10.in-addr.arpa.  IN      PTR     box3.labo.org.

1.0.0.10.in-addr.arpa.  IN      PTR     fw1.labo.org.

2.0.0.10.in-addr.arpa.  IN      PTR     fw2.labo.org.

On peut vérifier la syntaxe avec l'outil dlint
et bien sur penser a redemarrer bind9 avec
/etc/init.d/bind9 restart
dans les postes clients il faut bien sur penser a modifier le fichier /etc/resolv.conf

search labo.org
nameserver 10.0.0.4

Et finalement il est intéressant de sécuriser un chouia notre dns en modifiant named.conf.options

cat /etc/bind/named.conf.options

options {

        directory "/var/cache/bind";



        // If there is a firewall between you and nameservers you want

        // to talk to, you might need to uncomment the query-source

        // directive below.  Previous versions of BIND always asked

        // questions using port 53, but BIND 8.1 and later use an unprivileged

        // port by default.



        // query-source address * port 53;



        // If your ISP provided one or more IP addresses for stable

        // nameservers, you probably want to use them as forwarders.

        // Uncomment the following block, and insert the addresses replacing

        // the all-0's placeholder.







forwarders {

                192.168.7.254;

        };



        // forwarders {

        //      0.0.0.0;

        // };



        auth-nxdomain no;    # conform to RFC1035

        Version "None your business";

        Allow-query     { 10.0.0.0/24; };

        Allow-transfer  { 10.0.0.2;

                          10.0.0.4;

                        };



};