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I'm having trouble querying a name server on a different network 192.168.56.0/24 for records that contain host, vm1, vm2, and vm3. And I do not understand why. Is there anyway someone can explain whats going on.

Ferrari

/etc/resolv.conf

# Generated by NetworkManager
search luxury.auto.ops
nameserver 172.45.20.3
nameserver 192.168.56.2

/etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4      localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.45.20.1 host
172.45.20.1 host host.oadese.ops

/etc/named.conf

options {
    directory       "/var/named";
    allow-query     { 127.0.0.1; 172.45.20.0/24; 192.168.56.2;};
    forwarders { 192.168.56.1; };
};

zone "localhost"{
    type master;
    file "named.localhost";
};

zone "luxury.auto.ops."{
    type master;
    file "mydb-for-luxury-auto-ops";
    allow-transfer { 172.45.20.4; };
};

zone "20.45.172.in-addr.arpa." {
    type master;
    file "mydb-for-172.45.20";
};

vi /etc/sysconfig/network-scripts/ifcfg-eth0

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
UUID=78aa1a9b-0607-492a-b7dc-55d6f76f05d5
DEVICE=eth0
ONBOOT=yes
DOMAIN=luxury.auto.ops
IPADDR=172.45.20.3
NETMASK=255.255.255.0
HWADDR=52:54:00:8d:9e:93
GATEWAY=172.45.20.1
DNS1=172.45.20.3
DNS2=192.168.56.2

vm1 192.168.56.2

/etc/named.conf

options {
        directory       "/var/named";
        allow-query     { 127.0.0.1; 192.168.56.0/24; 172.45.20.0/24;};
        forwarders { 192.168.56.1; };
};

zone "localhost"{
        type master;
        file "named.localhost";
};

zone "oadese.ops" {
        type master;
        file "mydb-for-oadese-ops";
};

zone "56.168.192.in-addr.arpa." {
        type master;
        file "mydb-for-192.168.56";
};

/var/named/mydb-for-oadese-ops

$TTL    3D
@       IN      SOA     vm1.oadese.ops.      hostmaster.oadese.ops.(
                2016010301       ; Serial
                8H      ; Refresh
                2H      ; Retry
                1W      ; Expire
                1D      ; Negative Cache TTL
);
@       IN      NS      vm1.oadese.ops.
vm1     IN      A       192.168.56.2
vm2     IN      A       192.168.56.3
vm3     IN      A       192.168.56.4
host    IN      A       192.168.56.1

[root@ferrari ~]# nslookup vm1
Server:     192.168.56.2
Address:    192.168.56.2#53

Non-authoritative answer:
Name:   vm1
Address: 192.168.56.2

[root@ferrari ~]# nslookup vm2
Server:     192.168.56.2
Address:    192.168.56.2#53

Non-authoritative answer:
Name:   vm2
Address: 192.168.56.3

[root@ferrari ~]# nslookup vm3
Server:     192.168.56.2
Address:    192.168.56.2#53

Non-authoritative answer:
Name:   vm3
Address: 192.168.56.4

[root@ferrari ~]# nslookup host
Server:     192.168.56.2
Address:    192.168.56.2#53

Non-authoritative answer:
Name:   host
Address: 192.168.56.1

[root@ferrari ~]# nslookup ferrari
Server:     172.45.20.3
Address:    172.45.20.3#53

Name:   ferrari.luxury.auto.ops
Address: 172.45.20.3

[root@ferrari ~]# host vm1
Host vm1 not found: 3(NXDOMAIN)
[root@ferrari ~]# host vm2
Host vm2 not found: 3(NXDOMAIN)
[root@ferrari ~]# host vm3
Host vm3 not found: 3(NXDOMAIN)
[root@ferrari ~]# host host
[root@ferrari ~]# host ferrari
ferrari.luxury.auto.ops has address 172.45.20.3

Mar 18 10:43:50 ferrari named[2242]: error (connection refused) resolving 'vm1.oadese.ops/A/IN': 192.168.56.2#53
Mar 18 10:43:50 ferrari named[2242]: error (network unreachable) resolving 'vm1.oadese.ops/A/IN': 2001:500:2f::f#53
Mar 18 10:43:50 ferrari named[2242]: error (connection refused) resolving './NS/IN': 192.168.56.2#53
Mar 18 10:43:50 ferrari named[2242]: error (network unreachable) resolving './NS/IN': 2001:500:2f::f#53
Mar 18 10:43:51 ferrari named[2242]: error (connection refused) resolving 'vm1/A/IN': 192.168.56.2#53
Mar 18 10:43:51 ferrari named[2242]: error (network unreachable) resolving 'vm1/A/IN': 2001:500:1::803f:235#53
Mar 18 10:43:51 ferrari named[2242]: error (network unreachable) resolving 'vm1/A/IN': 2001:7fe::53#53
  • Which IP addresses are not doing well the request, and to which name servers? – Rui F Ribeiro Mar 15 '18 at 20:59
  • @RuiFRibeiro I've edited the post take a look. – Ovie Mar 15 '18 at 21:05
0

In the second nameserver you defined a forwarder for the server itself. For your architecture should be:

forwarders { 172.45.20.3 };

There is also the matter of the search directive in /etc/resolv.conf; if you have got two domains, and only one there. For the resolver to try and add the domains to the queries for both of the domains, you have to use:

search luxury.auto.ops. oadese.ops.

By the way, do not forget the dots.

Furthermore, you are configuring VMs to ask different nameservers with different views. DNS resolvers do not work like that, the 2nd nameserver will only be used if the 1st one is down. If the 1st is up and says it does not know a DNS address, the 2nd one won't be queried.

If you want to have separated DNS domains in separated nameservers, make the domain of the other server a slave, and make it a master on the other server; other more cleaner choice is making one of the servers a master for the two domains, and the other a slave.

  • @RuiFRiberio I'm still having this issue. It worked yesterday, but it is not working today. – Ovie Mar 17 '18 at 21:18
  • @Ovie I talk about several things here. I tried to convey in the answer your setup has several limitations, and it will give problems as you describe it in the question. It does not surprise me you are still having problems. I cannot however guess what is happening with you. – Rui F Ribeiro Mar 17 '18 at 21:22
  • so, you recommend that I, should make the 172.45.20.3 DnS server a slave server right? – Ovie Mar 17 '18 at 21:24
  • It will work better than the current setup. btw, you seem to have forgot one of the networks in the allow-query section of one of the servers. – Rui F Ribeiro Mar 17 '18 at 21:25
  • so, I should only ever have 1 master server, and the rest slaves. – Ovie Mar 17 '18 at 21:32

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