DNS原理相關
DNS 爲Domain Name System(域名系統)的縮寫,它是一種將IP地址轉換成對應的主機名或將主機名轉換成與之相對應IP地址的一種服務機制。 其中通過域名解析出IP地址的叫做正向解析,通過IP地址解析出域名的叫做反向解析。 DNS使用TCP和UDP, 端口號都是53, 但它主要使用UDP,服務器之間備份使用TCP。
全世界只有13臺“根”服務器,1個主根服務器放在美國,其他12臺爲輔根服務器,DNS服務器根據角色可以分爲:主DNS, 從DNS, 緩存DNS服務器,DNS轉發服務器。
軟件下載地址:https://download.samba.org/pub/samba/stable/
測試環境:
[root@light src]# cat /etc/centos-release && uname -r CentOS release 6.6 (Final) 2.6.32-504.el6.x86_64
安裝環境: 安裝開發工具和庫包
yum groupinstall "Development Tools" "Development Libraries" yum provides "*/filename" //如果提示依賴某filename,使用此命令查找依賴包
安裝過程:
[root@light src]# tar -zxvf bind-9.10.2.tar.gz [root@light src]# cd bind-9.10.2 [root@light bind-9.10.2]# ./configure --prefix=/usr/local/named --enable-threads --with-openssl --with-libxml2 --sysconfdir=/etc [root@light bind-9.10.2]# make && make install [root@light bind-9.10.2]# echo $? 0 [root@light bind-9.10.2]# groupadd -g 53 -r named [root@light bind-9.10.2]# useradd -g named -r named [root@light bind-9.10.2]# mkdir /var/named
配置與測試:
[root@light bind-9.10.2]# vi /etc/named/named.conf options { directory "/var/named"; //表示默認的數據庫文件在/var/named中 若沒有需手動創建 pid-file "/var/run/named/named.pid"; //運行的PID文件路徑,用於使用其他用戶啓動 }; zone "."{ //創建root域 type hint; file "named.ca"; }; zone "localhost" { //創建 localhost域 type master; file "named.local"; }; zone "0.0.127.in-addr.arpa" { //localhost的反解析 type master; file "127.0.0.zone"; }; [root@light named]# /usr/local/named/bin/dig -t NS . > /var/named/named.ca [root@light named]# /usr/local/named/sbin/rndc-confgen > /etc/named/rndc.conf [root@light sbin]# tail -12 /etc/named/rndc.conf >> /etc/named/named.conf # Use with the following in named.conf, adjusting the allow list as needed: # key "rndc-key" { # algorithm hmac-md5; # secret "4wq5U0hWysn2vygWCUloLw=="; # }; # # controls { # inet 127.0.0.1 port 953 # allow { 127.0.0.1; } keys { "rndc-key"; }; # }; # End of named.conf [root@light ~]# vi /var/named/named.local $TTL 1D @ IN SOA localhost. root ( 2015013001 1H 15M 1W 1D ) IN NS @ IN A 127.0.0.1 [root@light ~]# vi /var/named/127.0.0.zone [root@light ~]# cat /var/named/127.0.0.zone $TTl 1D @ IN SOA @ root.localhost. ( 2015013001 1H 15M 1W 1D ) IN NS localhost. 1 IN PTR localhost.
權限設置:
[root@light ~]# chown root:named /etc/named/* [root@light ~]# chown -R named:named /var/named [root@light ~]# chmod 640 /etc/named/* [root@light ~]# chmod 640 /var/named/*
檢查文件正反解析:
[root@light sbin]# ./named-checkzone "localhost" /var/named/named.local zone localhost/IN: loaded serial 2015013001 OK [root@light sbin]# ./named-checkzone "0.0.127.in-addr.arpa" /var/named/named.local zone 0.0.127.in-addr.arpa/IN: loaded serial 2015013001 OK [root@light sbin]# ./named-checkzone "0.0.127.in-addr.arpa" /var/named/127.0.0.zone zone 0.0.127.in-addr.arpa/IN: loaded serial 2015013001 OK [root@light ~]# /usr/local/named/sbin/rndc-confgen -r /dev/urandom -a // 這一步是生成 rndc.key, 如果沒有這個key, namd啓動報錯。 wrote key file "/etc/named/rndc.key" [root@light ~]# chown named:named /etc/named/rndc.key [root@light ~]# /usr/local/named/sbin/named #啓動服務
增加一個域名:
[root@light ~]# vi /etc/named/named.conf //添加進腳本中 zone "bright.com" { type master; file "bright.com.zone"; }; zone "1.168.192.in-addr.arpa" { type master; file "192.168.1.zone"; }; [root@light ~]# vi /var/named/bright.com.zone //創建並編輯 $TTL 86400 @ IN SOA bright.com. root.bright.com. ( 2015013001 1H 15M 1W 1D ) IN NS bright.com. IN A 192.168.1.52 [root@light ~]# vi /var/named/192.168.1.zone //創建並編輯 $TTL 1D @ IN SOA bright.com. root.bright.com. ( 2015013001 1H 15M 1W 1D ) IN NS bright.com. 52 IN PTR bright.com.
同上測試是否正常解析
[root@light sbin]# pwd /usr/local/named/sbin [root@light sbin]# ./named-checkzone "bright.com" /var/named/bright.com.zone zone bright.com/IN: loaded serial 2015013001 OK [root@light sbin]# ./named-checkzone "1.168.192.in-addr.arpa" /var/named/192.168.1.zone zone 1.168.192.in-addr.arpa/IN: loaded serial 2015013001 OK
編寫啓動腳本 (named的配置文件路徑按需修改!)
[root@light ~]# vi /etc/rc.d/init.d/named #!/bin/bash # # description: named daemon 描述信息 # chkconfig: - 25 88 啓動和關閉級別 # # 啓動named的pid文件、其實文件路徑我們都可以自己指定的 pidFile=/var/run/named.pid # 啓動服務時的鎖文件、判斷一個服務是不是啓動是靠這個鎖文件的 lockFile=/var/lock/subsys/named # named的配置文件路徑 confFile=/etc/named.conf # 判斷/etc/rc.d/init.d/functions路徑下的functios是否存在這個文件、存在就sources進來 [ -r /etc/rc.d/init.d/functions ] && . /etc/rc.d/init.d/functions # 定義啓動方法 start() { # 判斷鎖文件是否存在、如果存在就說服務已經啓動並退出 if [ -e $lockFile ]; then echo "named is already running..." exit 0 fi # 打印服務已經啓動的信息 echo -n "Starting named:" # 調用functions中的daemon方法、並用--pidfile指定pid文件位置、指定用戶和配置文件、我們本來是直接啓用named的、現在利用daemon這個函數來啓用這個服務、他會獲得很多額外的屬性、如果成功了會幫我們打印什麼[ OK ]的、還可以做判斷 daemon --pidfile "$pidFile" /usr/local/named/sbin/named -u named -c "$confFile" RETVAL=$? echo # 判斷上面的命令是否執行成功、說明啓動成功 if [ $RETVAL -eq 0 ]; then # 如果判斷成功、就創建鎖文件 touch $lockFile return $RETVAL else # 否則、就是失敗了、那就刪除鎖文件和pid文件 rm -f $lockFile $pidFile return 1 fi } # 定義停止方法 stop() { # 如果鎖文件不存在 if [ ! -e $lockFile ]; then # 說明服務還沒有啓動 echo "named is stopped." fi echo -n "Stopping named:" killproc named RETVAL=$? echo # 判斷以上的命令是否執行停止成功、如果成功 if [ $RETVAL -eq 0 ];then # 刪除鎖文件和pid文件 rm -f $lockFile $pidFile return 0 else # 否則打印說沒能正常停止 echo "Cannot stop named." # 調用functions中的函數、會打印失敗 failure return 1 fi } # 定義重啓服務 restart() { # 調用停止方法 stop # 睡眠2秒 sleep 2 # 調用啓動方法 start } # 定義重新加載服務方法 reload() { echo -n "Reloading named: " # killprco HUP信號、named進程的信號 killproc named -HUP RETVAL=$? echo return $RETVAL } # 定義服務狀態 status() { if pidof named &> /dev/null; then echo -n "named is running..." success echo else echo -n "named is stopped..." success echo fi } # 定義錯誤提示信息 usage() { echo "Usage: named {start|stop|restart|status|reload}" } case $1 in start) start ;; stop) stop ;; restart) restart ;; status) status ;; reload) reload ;; *) usage exit 4 ;; esac
加入服務
chmod 755 /etc/rc.d/init.d/named chkconfig --add named chkconfig --level 345 named on service named start(stop|status|reload|restart)