239 lines
6.7 KiB
Markdown
239 lines
6.7 KiB
Markdown
# DNS Interne
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Il y a deux types principaux de configurations possible pour les serveurs DNS :
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- Les serveurs récursif-cache qui servent pour résoudre les adresses.
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- Les serveurs d’autorité qui servent à faire la correspondance IP-NOM.
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On conseille généralement de ne pas faire les deux sur un même serveur. En effet, une attaque peut être menée sur un serveur récursif ce qui impacterait le service d'autorité. Grâce à la gestion de vu pas de risque vu que seul les conteneurs / VM on accès au récursif.
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## Le conteneur
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Numéro 107 (Beta)
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#### Trois interfaces
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- eth0 : vmbr1 / VLAN 10 / IP 10.0.0.253 / GW 10.0.0.254
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- eth1 : vmbr1 / VLAN 20 / IP 10.0.1.253 / GW 10.0.1.254
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- eth2 : vmbr1 / VLAN 30 / IP 10.0.2.253 / GW 10.0.2.254
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- eth3 : vmbr2 / VLAN 100 / IP 10.1.0.107 / GW 10.1.0.254
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### Le proxy
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#### /etc/apt/apt.conf.d/01proxy
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```
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Acquire::http {
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Proxy "http://10.0.2.252:9999";
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};
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```
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## Installation
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Faites par le playbook Ansible.
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```
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apt-get update
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apt-get install -y bind9 dnsutils
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```
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Création des répertoires nécessaire,
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```
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mkdir /var/log/dns/
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mkdir /etc/bind/zones
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touch /var/log/dns/query.log
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touch /var/log/dns/error.log
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chown bind:bind /var/log/dns/ -R
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```
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## Configuration
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### /etc/bind/named.conf.options
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Configuration globale de bind9. Remplacer le contenu par ce qui suit,
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```
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options {
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directory "/var/cache/bind";
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dnssec-validation auto;
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auth-nxdomain no;
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listen-on { any;};
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version "V1.0";
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forwarders {
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80.67.169.12;
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80.67.169.40;
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};
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forward only;
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};
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logging {
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channel query_log {
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file "/var/log/dns/query.log";
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severity debug 10;
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print-category yes;
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print-time yes;
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print-severity yes;
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};
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channel error_log {
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file "/var/log/dns/error.log";
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severity error;
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print-category yes;
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print-time yes;
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print-severity yes;
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};
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category queries { query_log;};
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category security { error_log;};
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};
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```
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## Gestion par vue
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Pour savoir depuis quelle zone de notre réseau la requête est faites nous allons utiliser les vues de bind9 ainsi le serveur pourra renvoyer une IP différente en fonction de la zone.
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Le serveur aura une pâte sur chaque zone comme décrit ci-dessous :
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- DMZ -> 10.0.0.253
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- PROXY -> 10.0.1.253
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- INT -> 10.0.2.253
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On définit deux zones DNS, une première, **front**, qui regroupe les zones DMZ et PROXY et une seconde, **back** qui regroupe les zones PROXY et INT.
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### /etc/bind/named.conf
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```
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include "/etc/bind/named.conf.options";
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acl front {
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127.0.0.1;
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10.0.0.0/24;
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};
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acl back {
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10.0.1.0/24;
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10.0.2.0/24;
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};
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view "internalfront" {
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recursion yes;
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match-clients {front;};
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allow-query {front;};
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allow-recursion {front;};
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allow-query-cache {front;};
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include "/etc/bind/named.conf.default-zones";
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include "/etc/bind/zones.rfc1918";
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zone "krhacken.org" {
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notify no;
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type master;
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file "/etc/bind/zones/db.krhacken.org.front";
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};
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zone "1.0.10.in-addr.arpa" {
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notify no;
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type master;
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file "/etc/bind/zones/db.krhacken.org.intrafront.rev";
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};
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};
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view "internalback" {
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recursion yes;
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match-clients {back;};
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allow-query {back;};
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allow-recursion {back;};
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allow-query-cache {back;};
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include "/etc/bind/named.conf.default-zones";
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include "/etc/bind/zones.rfc1918";
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zone "krhacken.org" {
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notify no;
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type master;
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file "/etc/bind/zones/db.krhacken.org.back";
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};
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zone "1.1.10.in-addr.arpa" {
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notify no;
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type master;
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file "/etc/bind/zones/db.krhacken.org.intraback.rev";
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};
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};
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```
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### /etc/bind/zones/db.krhacken.org.front
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```
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$TTL 10800
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@ IN SOA dns.krhacken.org. dnsmaster.krhacken.org. (
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2015010101 ; Serial
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5400 ; Refresh
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2700 ; Retry
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2419200 ; Expire
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300 ) ; Negative TTL
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IN NS dns.krhacken.org. ;Nom du serveur
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alpha.fw IN A 10.0.0.1
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beta.fw IN A 10.0.0.2
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vip.fw IN A 10.0.0.3
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alpha.haproxy IN A 10.0.0.4
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beta.haproxy IN A 10.0.0.5
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vip.haproxy IN A 10.0.0.6
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proxyint IN A 10.0.0.7
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mail IN A 10.0.0.10
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dns IN A 10.0.0.253
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alpha.nginx IN A 10.0.1.3
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beta.nginx IN A 10.0.1.4
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```
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### /etc/bind/zones/db.krhacken.org.back
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```
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$TTL 10800
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@ IN SOA dns.krhacken.org. dnsmaster.krhacken.org. (
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2015010101 ; Serial
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5400 ; Refresh
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2700 ; Retry
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2419200 ; Expire
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300 ) ; Negative TTL
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IN NS dns.krhacken.org. ;Nom du serveur
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alpha.haproxy IN A 10.0.1.1
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beta.haproxy IN A 10.0.1.2
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alpha.ldap IN A 10.0.2.1
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beta.ldap IN A 10.0.2.2
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vip.ldap IN A 10.0.2.3
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alpha.nginx IN A 10.0.2.4
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beta.nginx IN A 10.0.2.5
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dns IN A 10.0.2.253
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proxyint IN A 10.0.2.254
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```
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INT
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### /etc/bind/zones/db.krhacken.org.intrafront.rev
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```
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REV
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$TTL 10800
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@ IN SOA dns.krhacken.org. dnsmaster.krhacken.org. (
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2015021102 ; Serial
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5400 ; Refresh
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2700 ; Retry
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2419200 ; Expire
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300 ) ; Negative TTL
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@ IN NS dns.krhacken.org.
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253 IN PTR dns.krhacken.org.
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1 IN PTR alpha.fw.krhacken.org.
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2 IN PTR beta.fw.krhacken.org.
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3 IN PTR vip.fw.krhacken.org.
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4 IN PTR alpha.haproxy.krhacken.org.
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5 IN PTR beta.haproxy.krhacken.org.
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6 IN PTR vip.haproxy.krhacken.org.
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7 IN PTR proxyint.krhacken.org.
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10 IN PTR mail.krhacken.org.
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3 IN PTR alpha.nginx.krhacken.org.
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4 IN PTR beta.nginx.krhacken.org.
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```
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### /etc/bind/zones/db.krhacken.org.intraback.rev
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```
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REV
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$TTL 10800
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@ IN SOA dns.krhacken.org. dnsmaster.krhacken.org. (
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2015021102 ; Serial
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5400 ; Refresh
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2700 ; Retry
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2419200 ; Expire
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300 ) ; Negative TTL
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@ IN NS dns.krhacken.org.
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253 IN PTR dns.krhacken.org.
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1 IN PTR alpha.haproxy.krhacken.org.
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2 IN PTR beta.haproxy.krhacken.org.
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1 IN PTR alpha.ldap.krhacken.org.
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2 IN PTR beta.ldap.krhacken.org.
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3 IN PTR vip.ldap.krhacken.org.
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4 IN PTR alpha.nginx.krhacken.org.
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5 IN PTR beta.nginx.krhacken.org.
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254 IN PTR proxyint.krhacken.org.
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```
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Redémarrage de bind9
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```
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systemctl restart bind9
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```
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