Estou tentando configurar um servidor DNS básico que apenas encaminha solicitações de outros servidores DNS.
Instalei o bind9 e editei o arquivo /etc/bind/named.conf.options como abaixo.
options {
directory "/var/cache/bind";
// If there is a firewall between you and nameservers you want
// to talk to, you may need to fix the firewall to allow multiple
// ports to talk. See http://www.kb.cert.org/vuls/id/800113
// 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 {
8.8.8.8;
};
//========================================================================
// If BIND logs error messages about the root key being expired,
// you will need to update your keys. See https://www.isc.org/bind-keys
//========================================================================
dnssec-validation auto;
auth-nxdomain no; # conform to RFC1035
listen-on-v6 { any; };
};
Por isso, deve encaminhar solicitações para o servidor DNS do Google (trivial, mas pretendo adicionar mais em uma data posterior).
Em seguida, editei /etc/network/interfaces para adicionar o servidor DNS como um loopback (127.0.0.1) para teste. Depois, executei sudo service bind9 start e sudo ifdown ens33 && sudo ifup ens33 para exibir tudo.
Mas isso não parece ter funcionado. Eu executei um dig google.com e ele não está resolvendo o próprio pedido (127.0.0.1).
; <<>> DiG 9.10.3-P4-Ubuntu <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63300
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 276 IN A 216.58.220.110
;; Query time: 0 msec
;; SERVER: 192.168.0.3#53(192.168.0.3)
;; WHEN: Sun Feb 26 16:43:05 PST 2017
;; MSG SIZE rcvd: 55
Eu também tentei conectar-me ao servidor DNS externamente através de uma máquina com Windows 7, mas parece não resolver nada, uma consulta nslookup da máquina com Windows 7 fornece os seguintes resultados.
nslookup google.com
Server: UnKnown
Address: 192.168.0.188
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to UnKnown timed-out
Eu executei um sudo service bind9 status , o que me diz que o serviço está ativo, mas parece que tem alguns problemas de resolução.
â— bind9.service - BIND Domain Name Server
Loaded: loaded (/lib/systemd/system/bind9.service; enabled; vendor preset: enabled)
Drop-In: /run/systemd/generator/bind9.service.d
└─50-insserv.conf-$named.conf
Active: active (running) since Sun 2017-02-26 16:26:44 PST; 20min ago
Docs: man:named(8)
Process: 1329 ExecStop=/usr/sbin/rndc stop (code=exited, status=0/SUCCESS)
Main PID: 1334 (named)
Tasks: 7 (limit: 512)
CGroup: /system.slice/bind9.service
└─1334 /usr/sbin/named -f -u bind
Feb 26 16:39:24 ubuntu named[1334]: network unreachable resolving '151.in-addr.arpa/DNSKEY/IN': 2001:500:2f::f#53
Feb 26 16:39:24 ubuntu named[1334]: REFUSED unexpected RCODE resolving '151.in-addr.arpa/DNSKEY/IN': 202.12.27.33#53
Feb 26 16:39:24 ubuntu named[1334]: network unreachable resolving '151.in-addr.arpa/DNSKEY/IN': 2001:dc3::35#53
Feb 26 16:39:24 ubuntu named[1334]: REFUSED unexpected RCODE resolving '151.in-addr.arpa/DNSKEY/IN': 192.112.36.4#53
Feb 26 16:39:24 ubuntu named[1334]: REFUSED unexpected RCODE resolving '151.in-addr.arpa/DNSKEY/IN': 192.228.79.201#53
Feb 26 16:39:24 ubuntu named[1334]: network unreachable resolving '151.in-addr.arpa/DNSKEY/IN': 2001:500:84::b#53
Feb 26 16:39:24 ubuntu named[1334]: network unreachable resolving '151.in-addr.arpa/DNSKEY/IN': 2001:500:12::d0d#53
Feb 26 16:39:24 ubuntu named[1334]: REFUSED unexpected RCODE resolving '151.in-addr.arpa/DNSKEY/IN': 198.97.190.53#53
Feb 26 16:39:24 ubuntu named[1334]: network unreachable resolving '151.in-addr.arpa/DNSKEY/IN': 2001:500:1::53#53
Feb 26 16:39:24 ubuntu named[1334]: broken trust chain resolving '69.65.101.151.in-addr.arpa/PTR/IN': 8.8.8.8#53
Alguém consegue identificar o que eu fiz de errado ou me dar dicas sobre o que devo verificar em seguida?