RHCE課程-RH253Linux服務(wù)器架設(shè)筆記四-DHCP服務(wù)器配置上課講義

1、Good is good, but better carries it.精益求精，善益求善。RHCE課程-RH253Linux服務(wù)器架設(shè)筆記四-DHCP服務(wù)器配置-RHCE課程-RH253Linux服務(wù)器架設(shè)筆記四-DHCP服務(wù)器配置今天我們的課程是DHCP服務(wù)器的架設(shè),在安裝虛擬機(jī)的時(shí)候網(wǎng)卡選擇橋接的就可以.DHCP基于客戶/服務(wù)器模式。當(dāng)DHCP客戶端啟動(dòng)時(shí)，它會(huì)自動(dòng)與DHCP服務(wù)器通信，由DHCP服務(wù)器為DHCP客戶端提供自動(dòng)分配IP地址的服務(wù)。當(dāng)然高級(jí)的DHCP，不光只是分配地址這么簡(jiǎn)單,今天我們的課程只是架設(shè)一個(gè)普通的DHCP的服務(wù)器,client端能獲取到上網(wǎng)必須的網(wǎng)絡(luò)配置信息安裝

2、了DHCP服務(wù)軟件的服務(wù)器稱為DHCP服務(wù)器，而啟用了DHCP功能的客戶機(jī)稱為DHCP客戶端,DHCP服務(wù)器是以地址租約的方式為DHCP客戶端提供服務(wù)的，它有以下兩種方式。限定租期永久租用學(xué)DHCP服務(wù)器，就一定要知道DHCP服務(wù)器的工作原理,不然你就白學(xué)了DHCPDISCOVER（DHCP發(fā)現(xiàn)）DHCPOFFER（DHCP提供）DHCPREQUEST（DHCP請(qǐng)求）DHCPACK（DHCP確認(rèn)）這個(gè)4個(gè)步驟，是client獲取IP地址必經(jīng)的步驟在第二步，DHCP提供的時(shí)候，服務(wù)器已經(jīng)給client分配了IP地址,第二部分分給client的IP地址是臨時(shí)的，client得到這個(gè)IP地址后，會(huì)發(fā)

3、出DHCP請(qǐng)求,請(qǐng)求租用這個(gè)地址，服務(wù)器收到請(qǐng)求后，就會(huì)正式把這個(gè)地址分配給client，繼而向client發(fā)送DHCP確認(rèn)。這個(gè)四步主要是應(yīng)對(duì)同一網(wǎng)絡(luò)多個(gè)DHCP服務(wù)器后臺(tái)進(jìn)程：dhcpd腳本：/etc/rc.d/init.d/dhcpd使用端口：67所需RPM包：dhcp相關(guān)RPM包：dhcp-devel-3.0.5-7.el5.i386.rpmdhcpv6-0.10-33.el5.i386.rpmdhcpv6_client-0.10-33.el5.i386.rpm配置文件：/etc/dhcpd.conf日志：/var/log/xferlog68號(hào)是網(wǎng)絡(luò)啟動(dòng)模式使用的,暫時(shí)不討論再提示一點(diǎn)

4、吧，網(wǎng)絡(luò)啟動(dòng)方式也叫bootpc，這樣獲取的IP地址是不會(huì)受服務(wù)器的租期限制的，它永遠(yuǎn)有效好了，我們先安裝DHCP服務(wù)器編輯DHCP的主配置文件vim/etc/dhcpd.conf這里的意思是see的路勁是一個(gè)模板我們把這個(gè)文件內(nèi)容導(dǎo)進(jìn)來,在末行模式運(yùn)行以下命令末行模式使用:r文件名:r/usr/share/doc/dhcp*/dhcpd.conf.sample這樣模板就被導(dǎo)入進(jìn)來了使用模板的好處第一自己寫配置文件，麻煩還容易出錯(cuò)第二使用模板架設(shè)很快，只需要修改幾個(gè)參數(shù)就OK了ddns-update-style類型定義所支持的DNS動(dòng)態(tài)更新類型（必選）,一般我們?cè)O(shè)置成關(guān)閉,interim和no

5、ne都是關(guān)閉的意思allow/ignoreclient-updates允許/忽略客戶機(jī)更新DNS記錄subnet網(wǎng)絡(luò)號(hào)netmask子網(wǎng)掩碼定義作用域（或IP子網(wǎng)）配置文件已經(jīng)說的很清楚了optionrouters,網(wǎng)關(guān)，我的網(wǎng)關(guān)是nis-domain局域網(wǎng)內(nèi)有nis服務(wù)器的，可以設(shè)置nis服務(wù)器的域名我沒有架設(shè)nis服務(wù)器，所以這行可以注釋了下一行是domain-name，域名我的是域名服務(wù)器是我這個(gè)機(jī)器的IP，linux當(dāng)然有超級(jí)域,linux也能實(shí)現(xiàn)中繼DHCP,相關(guān)設(shè)置參考HYPERLINK/27212/127548RHEL5企業(yè)級(jí)Linux服務(wù)攻略-第3季DHCP服務(wù)全攻略time-

6、offset：為客戶端指定格林威治時(shí)間偏移時(shí)間，單位秒，該選項(xiàng)可以在全局配置、局部配置均可使用。ntp-servers：NTP是時(shí)間服務(wù)器netbios-name-servers：是微軟的名字服務(wù)器NTP服務(wù)器，你可以設(shè)置一個(gè)外網(wǎng)的，如果覺得沒必要就可以不設(shè)置rangedynamic-bootp就是動(dòng)態(tài)分配的IP地址池，這個(gè)是IP地址是連在一起的地址池范圍下面兩行是默認(rèn)租期和最大租期，單位是秒如果你某個(gè)主機(jī)要固定獲取某個(gè)IP，就可以使用下面的功能，next-server這里用不上，意思就是下一個(gè)服務(wù)器，一般指向tftp的，一般是PXE網(wǎng)絡(luò)使用這個(gè)參數(shù)好了，保存退出重新啟動(dòng)服務(wù)記住，配置文件中的

7、一定要對(duì)應(yīng)，還有第一個(gè)參數(shù)ddns-update-styple必須要，一般就不會(huì)出什么問題了看下日志cat/var/log/messagesrootrhel5#cat/var/log/messagesMar2204:02:10rhel5syslogd1.4.1:restart.Mar2204:02:09rhel5nmbd24089:2009/03/2204:02:09,0nmbd/nmbd_workgroupdb.c:dump_workgroups(282)Mar2204:02:09rhel5nmbd24089:dump_workgroups()Mar2204:02:09rhel5nmbd24

8、089:dumpworkgrouponsubnet88:netmask=:Mar2204:02:09rhel5nmbd24089:WANXUAN(7)currentmasterbrowser=SERVERMar2204:02:09rhel5nmbd24089:WORKGROUP(6)currentmasterbrowser=LENOVO-A5A67FC0Mar2204:02:09rhel5nmbd24089:MYGROUP(1)currentmasterbrowser=RHEL5Mar2204:02:09rhel5nmbd24089:RHEL540849a03(SambaServerVersi

9、on3.0.25b-0.el5.4)Mar2208:38:43rhel5kernel:VFS:busyinodesonchangedmedia.Mar2208:38:49rhel5lastmessagerepeated7timesMar2208:48:06rhel5scim-bridge:PanelclienthasnotyetbeenpreparedMar2208:48:09rhel5PanelclienthasnotyetbeenpreparedMar2208:48:09rhel5scim-bridge:PanelclienthasnotyetbeenpreparedMar2208:53:

10、07rhel5kernel:VFS:busyinodesonchangedmedia.Mar2208:53:38rhel5lastmessagerepeated33timesMar2208:54:21rhel5lastmessagerepeated42timesMar2213:27:30rhel5PanelclienthasnotyetbeenpreparedMar2213:27:30rhel5scim-bridge:PanelclienthasnotyetbeenpreparedMar2213:29:09rhel5nmbd24089:2009/03/2213:29:09,0nmbd/nmbd

11、.c:terminate(58)Mar2213:29:09rhel5nmbd24089:GotSIGTERM:goingdown.Mar2213:34:09rhel5nmbd18273:2009/03/2213:34:09,0nmbd/nmbd.c:terminate(58)Mar2213:34:09rhel5nmbd18273:GotSIGTERM:goingdown.Mar2213:39:51rhel5nmbd18445:2009/03/2213:39:51,0nmbd/nmbd_become_lmb.c:become_local_master_stage2(396)Mar2213:39:

12、51rhel5nmbd18445:*Mar2213:39:51rhel5nmbd18445:Mar2213:39:51rhel5nmbd18445:SambanameserverRHEL5isnowalocalmasterbrowserforworkgroupMYGROUPonsubnet88Mar2213:39:51rhel5nmbd18445:Mar2213:39:51rhel5nmbd18445:*Mar2216:17:20rhel5nmbd18445:2009/03/2216:17:20,0nmbd/nmbd.c:terminate(58)Mar2216:17:20rhel5nmbd1

13、8445:GotSIGTERM:goingdown.Mar2216:22:51rhel5nmbd23030:2009/03/2216:22:51,0nmbd/nmbd_become_lmb.c:become_local_master_stage2(396)Mar2216:22:51rhel5nmbd23030:*Mar2216:22:51rhel5nmbd23030:Mar2216:22:51rhel5nmbd23030:SambanameserverRHEL5isnowalocalmasterbrowserforworkgroupMYGROUPonsubnet88Mar2216:22:51r

14、hel5nmbd23030:Mar2216:22:51rhel5nmbd23030:*Mar2216:28:33rhel5nmbd23030:2009/03/2216:28:33,0nmbd/nmbd.c:terminate(58)Mar2216:28:33rhel5nmbd23030:GotSIGTERM:goingdown.Mar2216:34:15rhel5nmbd23366:2009/03/2216:34:15,0nmbd/nmbd_become_lmb.c:become_local_master_stage2(396)Mar2216:34:15rhel5nmbd23366:*Mar2

15、216:34:15rhel5nmbd23366:Mar2216:34:15rhel5nmbd23366:SambanameserverRHEL5isnowalocalmasterbrowserforworkgroupMYGROUPonsubnet88Mar2216:34:15rhel5nmbd23366:Mar2216:34:15rhel5nmbd23366:*Mar2310:44:21rhel5kernel:VFS:busyinodesonchangedmedia.Mar2310:44:26rhel5lastmessagerepeated7timesMar2314:01:09rhel5dhc

16、pd:WARNING:Hostdeclarationsareglobal.Theyarenotlimitedtothescopeyoudeclaredthemin.Mar2314:01:10rhel5dhcpd:dhcpdshutdownsucceededMar2314:01:10rhel5dhcpd:InternetSystemsConsortiumDHCPServerV3.0.5-RedHatMar2314:01:10rhel5dhcpd:Copyright2004-2006InternetSystemsConsortium.Mar2314:01:10rhel5dhcpd:Allright

17、sreserved.Mar2314:01:10rhel5dhcpd:Forinfo,pleasevisitHYPERLINK/sw/dhcp/url/sw/dhcp/urlMar2314:01:10rhel5dhcpd:WARNING:Hostdeclarationsareglobal.Theyarenotlimitedtothescopeyoudeclaredthemin.Mar2314:01:10rhel5dhcpd:Wrote0deletedhostdeclstoleasesfile.Mar2314:01:10rhel5dhcpd:Wrote0newdynamichostdeclstol

18、easesfile.Mar2314:01:10rhel5dhcpd:Wrote0leasestoleasesfile.Mar2314:01:10rhel5dhcpd:ListeningonLPF/eth0/00:0c:29:ec:fd:83/192.168.0/24Mar2314:01:11rhel5dhcpd:SendingonLPF/eth0/00:0c:29:ec:fd:83/192.168.0/24Mar2314:01:11rhel5dhcpd:SendingonSocket/fallback/fallback-netMar2314:01:11rhel5dhcpd:dhcpdstartupsucceededrootrhel5#現(xiàn)在我們來測(cè)試,使用client來獲取IP：dhclient臨時(shí)獲取一個(gè)IP地址,重新啟動(dòng)網(wǎng)卡失效,獲取的是54我們來看看服務(wù)器的日志看明白日志了嗎？client的請(qǐng)求我的linuxDHCP是收到了linux的DHCP是從后面開始獲取的,從高位開始分配的查看/var/lib/dhcpd/dhcpd.leases這個(gè)文件，可以看到被租出去的IP地址和相關(guān)信息這個(gè)很簡(jiǎn)單，大家應(yīng)該很容易看懂DHCP中繼，一般使用路由器實(shí)現(xiàn),很少使用主機(jī)來做這個(gè)文件/etc/sysconfig