bind + dhcpd 實現 動態 ddns

目標:

當客戶擷取 DHCP IP 位址後, 把當前使用中的主機名稱向 BIND 伺服器自動註冊, 實現自動網域名稱解析功能

 

原理:

bind 用於網域名稱解析,  為避免所有使用者都能夠用於更新 dns 伺服器, 利用密鑰進行資料更新驗證

dhcpd 在分配 IP 位址同時, 把 DNS 更新密鑰同時發送給客戶, 客戶自動向 BIND 伺服器進行註冊

 

dns 伺服器端軟體安裝

[root@station149 /]# yum install -y bind*Installed:  bind.x86_64 32:9.8.2-0.17.rc1.el6_4.6                         bind-chroot.x86_64 32:9.8.2-0.17.rc1.el6_4.6  bind-devel.x86_64 32:9.8.2-0.17.rc1.el6_4.6                   bind-dyndb-ldap.x86_64 0:2.3-5.el6  bind-sdb.x86_64 32:9.8.2-0.17.rc1.el6_4.6Complete!

建立密鑰

[root@station149 /]# rndc-confgen -r /dev/urandom -awrote key file "/etc/rndc.key"[root@station149 /]# chown named:named /etc/rndc.key[root@station149 /]# chown 644 /etc/rndc.key

 

當前密鑰檔案內容

key "rndckey" {        algorithm hmac-md5;        secret "qUGWW02EZVKUNMK/iorkgg==";};

把金鑰產製原料複製至 bind, dhcp 配置或可選使用 include 進行檔案匯入方法載入密鑰

bind 設定檔定義

vi /var/named/chroot/etc/named.conf

options {        directory "/var/named";        forwarders { 8.8.8.8; };};key "rndckey" {        algorithm hmac-md5;        secret "qUGWW02EZVKUNMK/iorkgg==";};#下面 定義只能夠通過本機 DHCP 進行 DNS 更新controls {        inet 127.0.0.1 allow { 127.0.0.1; } keys { rndckey; };};zone "cloud.com." IN {        type master;        file "cloud.com.master.zone";        allow-update { key rndckey; };};zone "48.168.192.in-addr.arpa." IN {        type master;        file "48.168.192.in-addr.arpa.master.zone";        allow-update { key rndckey; };};

正向 zone 設定檔
vi /var/named/chroot/var/named/cloud.com.master.zone

$TTL 86400@ IN SOA station149.cloud.com. root.station149.cloud.com. (        2014011510        1400        2300        25000        86400 )@       IN              NS      station149.cloud.com.station149              IN      A       192.168.48.149

 

反向 zone 設定檔

vi /var/named/chroot/var/named/48.168.192.in-addr.arpa.master.zone$TTL 86400@ IN SOA station149.cloud.com. root.station149.cloud.com. (        2014010810        1400        2300        25000        86400 )@       IN              NS      station149.cloud.com.149             IN      PTR     station149.cloud.com.

 

注: 當前只配置正向, 反向設定檔, 其他主機利用 DDNS 方法自動進行註冊

 

啟動 bind 並驗證

[root@station149 /]# chown named:named /var/named/chroot/var/named/*.zone[root@station149 /]# service named restart停止 named：                                               [確定]啟動 named：                                               [確定]

 dns 用戶端配置

[root@station149 ~]# vi /etc/resolv.confsearch clound.comnameserver 192.168.48.149

測試

[root@station149 ~]# host station149.cloud.comstation149.cloud.com has address 192.168.48.149[root@station149 ~]# host 192.168.48.149149.48.168.192.in-addr.arpa domain name pointer station149.cloud.com.[root@station149 ~]# host www.google.com.hkwww.google.com.hk is an alias for www-wide.l.google.com.www-wide.l.google.com has address 74.125.128.199www-wide.l.google.com has IPv6 address 2404:6800:4005:c00::c7

DHCP 伺服器配置

軟體安裝

[root@station149 ~]# yum install -y dhcpInstalled:  dhcp.x86_64 12:4.1.1-38.P1.el6.centosComplete!

vi /etc/dhcp/dhcpd.conf

key "rndckey" {        algorithm hmac-md5;        secret "qUGWW02EZVKUNMK/iorkgg==";};ddns-domainname "cloud.com.";ddns-update-style interim;ddns-rev-domainname "in-addr.arpa.";ddns-updates on;authoritative;#master server for this domain# Allow only the DHCP server to update DNSignore client-updates;allow unknown-clients;host pdc {   hardware ethernet 00:0B:2B:17:2F:00;   fixed-address 192.168.48.2;}zone  48.168.192.in-addr.arpa {        primary 127.0.0.1;        key rndckey;}zone cloud.com {        primary 127.0.0.1;        key rndckey;}subnet 192.168.48.0 netmask 255.255.255.0 {        range                        192.168.48.20 192.168.48.126;        default-lease-time              86400;        max-lease-time                172800;        option subnet-mask             255.255.255.0;        option broadcast-address        192.168.48.255;        option routers                 192.168.48.1;        option domain-name            "cloud.com.";        option domain-name-servers     192.168.48.149;}

啟動 dhcpd

service dhcpd start

 

需要注意的問題:

觀察 dhcp 伺服器

[root@station149 etc]# cat /var/lib/dhcpd/dhcpd.leases

# The format of this file is documented in the dhcpd.leases(5) manual page.# This lease file was written by isc-dhcp-4.1.1-P1server-duid "\000\001\000\001\032i\023^\000PV\201\350\247";lease 192.168.48.60 {  starts 3 2014/01/15 09:38:11;  ends 4 2014/01/16 09:38:11;  cltt 3 2014/01/15 09:38:11;  binding state active;  next binding state free;  hardware ethernet 00:50:56:81:72:9d;  client-hostname "terry";}

假如無法發現  client-hostname "terry";  資訊
則需要配置用戶端, 添加 DHCP_HOSTNAME 配置

 

參考用戶端配置資訊

[root@terry sysconfig]# cat /etc/sysconfig/networkNETWORKING=yesHOSTNAME=terryDHCP_HOSTNAME=terry

 

參考更新 bind 伺服器的日誌

Jan 15 17:40:42 station149 named-sdb[5646]: client 127.0.0.1#46556: signer "rndckey" approvedJan 15 17:40:42 station149 named-sdb[5646]: client 127.0.0.1#46556: updating zone 'cloud.com/IN': adding an RR at 'terry.cloud.com' AJan 15 17:40:42 station149 named-sdb[5646]: client 127.0.0.1#46556: updating zone 'cloud.com/IN': adding an RR at 'terry.cloud.com' TXTJan 15 17:40:42 station149 named-sdb[5646]: cloud.com.master.zone.jnl: create: permission deniedJan 15 17:40:42 station149 named-sdb[5646]: client 127.0.0.1#46556: updating zone 'cloud.com/IN': error: journal open failed: unexpected errorJan 15 17:40:42 station149 dhcpd: Unable to add forward map from terry.cloud.com. to 192.168.48.60: timed outJan 15 17:40:42 station149 dhcpd: DHCPREQUEST for 192.168.48.60 from 00:50:56:81:72:9d (terry) via eth0Jan 15 17:40:42 station149 dhcpd: DHCPACK on 192.168.48.60 to 00:50:56:81:72:9d (terry) via eth0

 

注意 /var/name/chroot/var/named 目錄是否可以被使用者  named 讀寫

 

假設一切正常,  /var/named/chroot/var/named 目錄下將會自動產生  jnl 尾碼檔案

[root@station149 named]# cd /var/named/chroot/var/named/[root@station149 named]# ls *.jnl48.168.192.in-addr.arpa.master.zone.jnl  cloud.com.master.zone.jnl

 

最後, 電腦會自動在 DNS 中註冊 terry.cloud.com 及對應 IP 位址, 驗證:

[root@station149 named]# host terry.cloud.comterry.cloud.com has address 192.168.48.60[root@station149 named]# host 192.168.48.6060.48.168.192.in-addr.arpa domain name pointer terry.cloud.com.