Za DNS server ćemo instalirati BIND 9, najrašireniji DNS server na internetu. Nakon što ga podesimo DNS server će resolvati domenu savica.net, forwardirati zajhtjeve za ostalim internim domenama prema nadležnim DNS poslužiteljima, te resolvati domene na internetu.
apt-get install bind9 dnsutils
DNS server ćemo podesiti tako da zna resolvati sve domene na internetu, a resolvane zapise ujedno čuva i u svom cache-u. Otvorite /etc/bind/named.conf i provjerite da unutra imate ovaj dio:
// prime the server with knowledge of the root servers
zone "." {
type hint;
file "/etc/bind/db.root";
};
Time smo DNS serveru dali do znanja da za sve domene pogleda popis root servera koji se nalazi u datoteci /etc/bind/db.root i pošalje jednom od njih upit.
Proverite još samo da na kraju imate liniju koja include-a naše lokalne opcije na kraju datoteke
include "/etc/bind/named.conf.local";
Provjerimo radi li naš DNS server:
grunf:~# nslookup google.com Server: 127.0.0.1 Address: 127.0.0.1#53 Non-authoritative answer: Name: google.com Address: 64.233.167.99 Name: google.com Address: 64.233.187.99 Name: google.com Address: 72.14.207.99
DNS server će biti glavni DNS server za domenu savica.net. Otvorimo datoteku /etc/bind/named.conf.local
nano /etc/bind/named.conf.local
i dodajmo slijedeće:
zone "savica.net" {
type master;
file "/etc/bind/zones/savica.net";
};
zone "0.29.10.in-addr.arpa" {
type master;
file "/etc/bind/zones/10.29.0.rev";
};
Kreirajmo prvo direktorij /etc/bind/zones
mkdir /etc/bind/zones
I kreirajmo u njemu datoteku savica.net:
nano /etc/bind/zones/savica.net
Upišimo odmah i par DNS zapisa:
$ORIGIN .
$TTL 300 ; 5 minutes
savica.net IN SOA ns1.savica.net. gog.savica.net. (
20080213 ; serial
300 ; refresh (5 minutes)
600 ; retry (10 minutes)
1209600 ; expire (2 weeks)
10800 ; minimum (3 hours)
)
NS ns1.savica.net.
NS ns2.savica.net.
$ORIGIN savica.net.
grunf A 10.29.0.2
grunf2 A 10.29.3.1
ns1 CNAME grunf
dc CNAME grunf
jabber CNAME grunf
voip CNAME grunf
ntp CNAME grunf
ts CNAME grunf
teamspeak CNAME grunf
ventrilo CNAME grunf
ns2 CNAME grunf2
Kreirajmo zatim 10.29.0.rev datoteku:
nano /etc/bind/zones/10.29.0.rev
I upišimo u nju PTR record barem za računalo koje je i DNS server (u ovom slučaju 10.29.0.2):
$ORIGIN .
$TTL 300 ; 5 minutes
0.29.10.in-addr.arpa IN SOA ns1.savica.net. hostmaster.savica.net. (
200802141 ; serial
7200 ; refresh (2 hours)
900 ; retry (15 minutes)
1209600 ; expire (2 weeks)
10800 ; minimum (3 hours)
)
NS ns1.savica.net.
NS ns2.savica.net.
$ORIGIN 0.29.10.in-addr.arpa.
2 PTR grunf.savica.net.
Dodajmo u /etc/resolv.conf i localhost (127.0.0.1), moja datoteka sada izgleda ovako:
search savica.net nameserver 127.0.0.1 nameserver 10.29.3.1
10.29.3.1 je sekundarni DNS server koji ćemo podesiti kasnije. Redoslijed ovih nameservera odlučuje o redoslijedu kako će server resolvati domene, s obzirom da smo na njemu podesili DNS server želimo da prvo “sebe pita” za svaku domenu. Ukoliko se slučajno DNS servis ugasi, upit će biti prosljeđen sekundardnom serveru (10.29.3.1).
Reloadajmo BIND i provjerimo radi li DNS server:
invoke-rc.d bind9 reload
grunf:~# nslookup ns1.savica.net Server: 127.0.0.1 Address: 127.0.0.1#53 ns1.savica.net canonical name = grunf.savica.net. Name: grunf.savica.net Address: 10.29.0.2
Kreirajmo prvo forward.conf datoteku, u njoj su smešteni dns-serveri na koje prosljeđujemo upite za domenama drugih mreža.
nano /etc/bind/forward.conf
U nju unesite sve prijateljske mreže s kojima ste spojeni i čije DNS-ove znate:
zone "wifihr." {
type forward;
forwarders { 10.14.16.1 ; 10.14.7.1 ; };
};
zone "14.10.in-addr.arpa" {
type forward;
forwarders { 10.14.16.1 ; 10.14.7.1 ; };
};
zone "dw." {
type forward;
forwarders { 10.29.1.251 ; };
};
zone "vb-vgw." {
type forward;
forwarders { 10.60.0.100 ; };
};
zone "vgw." {
type forward;
forwarders { 10.20.1.2 ; 10.20.3.1 ; };
};
zone "zgw." {
type forward;
forwarders { 10.5.142.32 ; 10.5.131.33 ; };
};
zone "znet." {
type forward;
forwarders { 10.168.4.2 ; 10.168.52.2 ; };
};
zone "vrw." {
type forward;
forwarders { 10.125.0.51 ; 10.14.7.1 ; };
};
Na kraju datoteke /etc/bind/named.conf.local dadajte liniju:
include "/etc/bind/forward.conf";
Reloadajmo BIND još jednom i provjerimo možemo li resolvati neku od forwardiranih domena, u mom slučaju je to .wifihr
invoke-rc.d bind9 reload
grunf:~# nslookup jabber.wifihr Server: 127.0.0.1 Address: 127.0.0.1#53 Non-authoritative answer: Name: jabber.wifihr Address: 10.14.16.2