I have the machine dnsserver with the bind9 service in domain ent.com. I also boot other machines: firewall and webserver. All machines are operated by Ubuntu-server-22.04.
I’ve configured these files:
/etc/bind/named.conf.options
listen-on {
192.168.0.0/24;
}
allow-query { any ;};
dnssec-validation auto;
forwarders {
192.168.0.1;
};
/etc/bind/named.conf.local
zone "ent.com" IN {
type master;
file "/etc/bind/forward.ent.com";
allow-transfer {192.168.0.211; };
also-notify {192.168.0.211; };
};
zone "0.168.192.in-addr.arpa" IN {
type master;
file "/etc/bind/reverse.ent.com";
};
The zone files.
/etc/bind/forward.ent.com
$TTL 604800
@ IN SOA dnsserver.ent.com. root.dnsserver.ent.com. (
5 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
@ IN NS dnsserver.ent.com.
@ IN A 192.168.0.211
dnsserver IN A 192.168.0.211
firewall IN A 192.168.0.201
mailserver IN A 192.168.0.212
webserver IN A 192.168.0.213
vault IN A 192.168.0.214
/etc/bind/forward.ent.com
$TTL 604800
@ IN SOA dnsserver.ent.com. root.dnsserver.ent.com. (
2 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
@ IN NS dnsserver.ent.com.
@ IN PTR ent.com.
211 IN PTR dnsserver.ent.com.
201 IN PTR firewall.ent.com.
212 IN PTR mailserver.ent.com.
213 IN PTR webserver.ent.com.
214 IN PTR vault.ent.com.
Commands named, checkconf and checkzone work without any issues.
So, when I connect to firewall and ping machines by their names, it works perfectly:
ilya@firewall:~$ nslookup dnsserver
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: dnsserver.ent.com
Address: 192.168.0.211
ilya@firewall:~$ ping webserver
PING webserver.ent.com (192.168.0.213) 56(84) bytes of data.
64 bytes from webserver.ent.com (192.168.0.213): icmp_seq=1 ttl=64 time=0.567 ms
64 bytes from webserver.ent.com (192.168.0.213): icmp_seq=2 ttl=64 time=0.657 ms
64 bytes from webserver.ent.com (192.168.0.213): icmp_seq=3 ttl=64 time=0.514 ms
^C
--- webserver.ent.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2028ms
rtt min/avg/max/mdev = 0.514/0.579/0.657/0.059 ms
But when try to ping names from dnsserver I have an error:
ilya@dnsserver:~$ ping webserver
ping: webserver: Temporary failure in name resolution
ilya@dnsserver:~$ ping firewall
ping: firewall: Temporary failure in name resolution
ilya@dnsserver:~$ nslookup webserver
Server: 127.0.0.53
Address: 127.0.0.53#53
** server can't find webserver: SERVFAIL
The dnsserver’s netplan configuration is here:
network:
version: 2
ethernets:
ens33:
dhcp4: no
match:
macaddress: 00:0c:29:7b:56:ad
set-name: ext0
addresses:
- 192.168.0.211/24
gateway4: 192.168.0.1
nameservers:
addresses: [192.168.0.211]
search: [ent.com]
Can’t find the mistake in my DNS server configuration. Could you help me?
