第1章 計算機硬件與組成原理..........................................................1

1.1 計算機硬件分類...........................................................................1

1.2 運維與服務器...............................................................................1

1.2.1 運維人員的核心職責 ...............................................................1

1.2.2 運維人員工資的主要戰場之服務器 .......................................2

1.2.3 服務器按外形分類 ...................................................................2

1.3 互聯網公司的服務器品牌...........................................................4

1.4 服務器品牌詳解及對應型號.......................................................4

1.4.1 Dell 服務器品牌.........................................................................4

1.4.2 IBM 品牌...................................................................................5

1.4.3 HP 品牌.................................................................................5

1.5 服務器(電腦)核心零部件介紹................................................6

1.5.1 電源..........................................................................................6

1.5.2 CPU 處理器 ............................................................................6

1.5.3 內存........................................................................................7

1.5.4 磁盤......................................................................................10

1.5.5 Raid 卡(陣列卡) ..................................................................10

1.5.6 光驅......................................................................................12

1.5.7 遠程管理卡 ..........................................................................12

1.5.8 機房里的服務器簡介 .............................................................12

1.5.9 主板(普通電腦) .................................................................14

1.6 電腦和服務器的主要構成圖解...........................................15

1.7 計算機系統基礎...................................................................16

1.7.1 馮·諾依曼計算機 ....................................................................16

1.7.2 計算機系統的基本工作原理 .................................................16

1.7.3 計算機數據記錄單位 .............................................................17

1.7.4 計算機常用計數制 .................................................................17

1.7.5 計算機中數據的表示 .............................................................18

第2章 LINUX 系統介紹與環境搭建準備......................................20

2.1 Linux 簡介..........................................................................20

2.1.1 什么是操作系統? .................................................................20

2.1.2 什么是 Linux?........................................................................21

2.2 Linux 的起源.........................................................................22

2.2.1 Unix 的歷史...........................................................................22

2.2.2 Unix 的 5 大優秀特性..............................................................23

2.2.3 Unix 操作系統的革命..............................................................23

2.2.4 Linux 的誕生..........................................................................24

2.2.5 Linux 的發展歷程.....................................................................24

2.3 Linux 核心概念知識.............................................................26

2.3.1 自由軟件與 FSF.......................................................................26

2.3.2 GNU 知識...............................................................................26

2.3.3 GPL 知識................................................................................27

2.3.4 FSF,GNU,GPL 小結....................................................................27

2.3.5 Linux 系統組成.........................................................................27

2.4 Linux 的特點.........................................................................28

2.4.1 Linux 為什么受歡迎?.............................................................28

2.5 LINUX 的應用領域..............................................................28

2.5.1 IT 服務器 Linux 系統應用領域................................................28

2.5.2 嵌入式 Linux 系統應用領域...................................................29

2.5.3 個人桌面 Linux 應用領域.......................................................29

2.6 如何選擇 Linux 的發行版...................................................29

2.6.1 Linux 的發行版本介紹.............................................................29

2.6.2 選擇適合的 Linux 系統學習...................................................30

2.6.3 下載 CentOS 系統 ISO 鏡像....................................................31

2.7 VMware 新建虛擬機 ............................................................33

2.7.1 虛擬機軟件介紹 .....................................................................33

2.7.2 為什么通過 VM 虛擬機軟件學習運維..................................33

2.7.3 下載安裝虛擬機 .....................................................................33

2.7.4 配置虛擬機 ..........................................................................34

2.8 遠程連接工具排錯...............................................................36

2.8.1 ip 服務器位置 .........................................................................36

2.8.2 道路是否暢通 .......................................................................36

2.8.3 遠程連接失敗常見原因 .......................................................36

2.9 總結...........................................................................................37

2.9.1 linux 歷史回顧 .........................................................................37

2.9.2 本章重點回顧 .........................................................................37

2.10 本章知識相關考試題.........................................................37

第3章 企業級 CentOS 7.6 操作系統的安裝...................................38

3.1 創建新的虛擬機(購買電腦)................................................38

3.1.1 選擇自定義配置 ...................................................................38

3.1.2 選擇虛擬機硬件兼容性===購買主機箱 ...............................39

3.1.3 安裝客戶機操作系統 ...............................................................39

3.1.4 選擇客戶機操作系統===安裝什么樣的系統 ........................40

3.1.5 命名虛擬機===專業規范 .......................................................40

3.1.6 處理器配置 ..........................................................................41

3.1.7 內存配置..............................................................................42

3.1.8 選擇網絡類型 .........................................................................42

3.1.9 選擇 I/O 控制類型..................................................................45

3.1.10 選擇磁盤類型 .......................................................................45

3.1.11 選擇磁盤............................................................................46

3.1.12 指定磁盤容量 .......................................................................46

3.1.13 指定磁盤文件 .......................................................................47

3.1.14 掛載 CentOS 鏡像.................................................................47

3.1.15 完成創建虛擬機----完成配置準備付款購買 ......................48

3.1.16 開機...........................................................................................49

3.2 安裝 CentOS7.5 系統...........................................................49

3.2.1 圖形化安裝 .........................................................................49

3.2.2 選擇安裝使用的語言 .............................................................50

3.2.3 設置時區.................................................................................50

3.2.4 最小化安裝系統 .....................................................................51

3.2.5 關閉 KDUMP........................................................................52

3.2.6 自定義分區 .........................................................................53

3.2.7 設置 IP 和主機名....................................................................60

3.2.8 設置 root 密碼 ........................................................................64

3.2.9 安裝結束重啟 .........................................................................65

3.3 系統安裝后的基本配置.......................................................65

3.3.1 登錄界面介紹 .........................................................................65

3.3.2 配置 VMware Workstation 整個網絡 ....................................66

3.3.3 使用 VMware 給虛擬機拍攝快照 .........................................70

3.4 額外安裝一些有用的軟件包...............................................71

3.5 本章重點回顧.......................................................................71

第4章 遠程連接管理 LINUX 實踐.................................................72

4.1 Xshell 整體優化.......................................................................72

4.2 顯示優化...........................................................................73

4.3 Xshell 基礎優化....................................................................73

4.4 xshell 使用連接.....................................................................76

第5章 LINUX 系統命令行入門基礎..............................................81

5.1 操作 LINUX 必知必會基礎知識........................................81

5.1.1 Linux 命令行組成結構.............................................................81

5.1.2 Linux 與 Windows 的目錄結構對比........................................81

5.2 在 LINUX 命令行下查看命令幫助....................................82

5.2.1 使用 man 獲取命令幫助信息................................................82

5.2.2 使用--help 參數獲取命令幫助信息.......................................83

5.2.3 使用 help 命令獲取 bash 內置命令幫助 ........................................................83

5.2.4 使用 info 獲取幫助信息.........................................................83

5.2.5 從互聯網搜索獲取命令幫助信息 .........................................83

5.3 LINUX 關機重啟注銷命令..................................................84

5.3.1 重啟或關機命令：shutdown.................................................84

5.3.2 關機與重啟命令：halt/poweroff/reboot........................................................84

5.3.3 關機、重啟和注銷的命令列表 .............................................84

5.3.4 Linux 命令行常用快捷鍵.........................................................85

第6章 LINUX 文件及目錄管理命令基礎......................................87

6.1 LINUX 文件及目錄核心命令..............................................87

6.1.1 pwd：顯示當前所在位置信息 ...............................................87

6.1.2 cd：切換目錄 ......................................................................87

6.1.3 tree：以樹形結構顯示目錄下內容........................................87

6.1.4 mkdir：創建目錄.....................................................................87

6.1.5 touch：創建文件或更改文件時間戳.....................................88

6.1.6 ls：顯示目錄下內容及屬性信息的命令................................88

6.1.7 cp：復制文件或目錄 ..............................................................88

6.1.8 mv：移動或重命名文件 .........................................................89

6.1.9 rm：刪除文件或目錄..............................................................89

6.2 LINUX 文件及目錄命令核心知識的試題及詳解........................................89

6.2.1 有關 cd/pwd/mkdir/ls 命令試題............................................89

第7章 LINUX 目錄文件與系統啟動知識......................................91

7.1 LINUX 系統目錄結構介紹..................................................91

7.1.1 Linux 與 Windows 目錄結構對比............................................91

7.1.2 Linux 系統目錄結構基本特點.................................................91

7.2 LINUX 的目錄結構詳解......................................................92

7.2.1 目錄層次標準 FHS..................................................................92

7.2.2 根下目錄結構詳解重要的 LINUX 系統文件介紹 ...........................................92

7.2.3 /etc 系統初始化及設置相關重要文件...................................94

7.2.4 網卡配置文件詳解： .............................................................95

7.2.5 /usr 目錄的重要知識介紹.......................................................95

7.2.6 /var 目錄下的路徑知識...........................................................96

7.2.7 /proc 下的重要路徑知識 ........................................................96

7.3 LINUX 系統啟動流程說明(重點)............................................97

7.3.1 CentOS6 系啟動流程 ...............................................................97

7.3.2 CentOS7 系啟動流程 .............................................................102

7.3.3 CentOS6 系與 7 系的啟動區別 .............................................103

第8章 Linux 文件過濾及內容編輯處理.......................................104

8.1 vi/vim：純文本編輯器詳解及快捷鍵.......................................104

8.1.1 基礎用法...................................................................................104

8.2 vim 模式轉換圖 ..................................................................104

8.2.1 命令模式...........................................................................105

8.2.2 編輯模式...........................................................................106

8.2.3 底行模式...........................................................................106

8.2.4 vi/vim 執行過程：.................................................................107

8.2.5 常見故障...........................................................................107

8.3 echo：顯示輸出文本內容..................................................107

8.4 cat：合并文件或查看文件內容.........................................108

8.5 more：分頁顯示文件內容 .................................................108

8.6 less：分頁顯示文件內容....................................................108

8.7 head：顯示文件內容頭部..................................................109

8.8 tail：顯示文件內容尾部 ....................................................109

8.9 grep:文本過濾工具 .............................................................109

8.10 tr：替換或刪除字符.........................................................109

8.10.1 重定向符號的核心知識 .....................................................109

8.11 有關 mkdir 命令的考題...................................................110

8.12 有關 cp/alias/unalias 命令的考題....................................110

8.12.1 配置別名過程 .....................................................................111

8.13 本章講解知識總結...........................................................112

第9章 Linux 文件類型及查找命令實踐.......................................113

9.1 Linux 文件屬性概述...........................................................113

9.2 Linux 文件類型及文件擴展名...........................................114

9.2.1 文件類型與擴展名介紹 .......................................................114

9.2.2 Linux 中的文件類型...............................................................114

9.2.3 Linux 文件類型詳細介紹.......................................................114

9.3 文件及目錄查找命令.........................................................114

9.3.1 file：顯示文件的類型 ...........................................................114

9.3.2 which：顯示命令的全路徑...................................................115

9.3.3 whereis：顯示命令及其相關文件全路徑......................................................115

9.3.4 locate：快速定位文件路徑(CentOS 7 不推薦)..............................................115

9.3.5 updatedb(不推薦) ..................................................................115

9.3.6 find：查找目錄下的文件......................................................115

9.3.7 xargs：將標準輸入轉換成命令行參數................................115

9.4 tar：打包壓縮命令 .............................................................115

9.4.1 創建壓縮包 .......................................................................115

9.4.2 查看壓縮包 .......................................................................116

9.4.3 解壓 默認是當前目錄 .........................................................116

9.4.4 創建壓縮包/tmp/conf.tar.gz 壓縮/etc/hosts /etc/services........................116

9.4.5 解壓到指定位置 ...................................................................117

9.4.6 tar 命令打包壓縮提示: Removing leading `/' from member names 背后原因分析 ...............117

9.5 date：顯示與設置系統時間...............................................118

9.5.1 date 以指定格式顯示 日期.................................................118

9.5.2 如何讓 linux 自動同步網絡時間 :ntpdate....................................................119

9.6 章節重點....................................................................................119

第10章 LINUX 文件更多核心屬性知識......................................120

10.1 用戶及用戶組...................................................................120

10.1.1 Linux 單用戶多任務.............................................................120

10.1.2 Linux 多用戶多任務.............................................................120

10.1.3 用戶(user)介紹..............................................................120

10.1.4 Linux 系統中用戶角色劃分.................................................121

10.1.5 Linux 系統中不同用戶角色對應的 UID 說明...............................................121

10.1.6 多用戶操作系統的安全 .....................................................121

10.1.7 用戶組(group)介紹........................................................121

10.1.8 創建用戶及用戶組命令 .....................................................122

10.2 文件的權限列...................................................................122

10.2.1 文件權限說明 .....................................................................122

10.3 文件的修改時間屬性列...................................................123

10.4 索引節點(inode)..........................................................123

10.4.1 什么是索引節點(inode)................................................123

10.4.2 查看文件內容與 inode 和 block 關系 ...................................123

10.4.3 inode 和 block 的特點 .........................................................124

10.4.4 查看和管理 inode...............................................................124

10.5 鏈接的概念.......................................................................125

10.5.1 硬鏈接.............................................................................125

10.5.2 軟鏈接知識與實踐 .............................................................125

10.5.3 【必會】企業面試：請描述 Linux 中軟鏈接和硬鏈接的區別.................126

10.6 章節重點與面試題...........................................................128

第11章 Linux 通配符與特殊符號知識應用實踐 ...................................................129

11.1 Linux 通配符與特殊符號簡介 .........................................129

11.2 Linux 通配符知識與實踐 .................................................129

11.2.1 通配符之*號的作用介紹與實踐 .......................................129

11.2.2 講解{}用途.......................................................................129

11.2.3 通配符之?號作用介紹與實踐 ...........................................129

11.2.4 通配符之[abcd]作用介紹與實踐.......................................129

11.2.5 通配符之[a-z]作用介紹與實踐..........................................129

11.2.6 通配符之[!abcd]作用介紹與實踐......................................129

11.3 Linux 特殊符號知識與實踐 .............................................130

11.3.1 與路徑和位置有關的特殊符號 .........................................130

11.3.2 不同引號特殊符號知識與實踐(重要) ...................................................130

11.3.3 重定向特殊符號知識與實踐(重要) .......................................................130

11.3.4 其他特殊符號知識與實踐(重要) .................................131

11.3.5 bash 中邏輯操作符系列......................................................131

11.4 Linux 通配符與特殊符號知識小結 .................................131

第12章 正則表達式........................................................................133

12.1 為何使用正則表達式.......................................................133

12.2 正則表達式分類...............................................................133

12.3 正則與通配符區別...........................................................133

12.3.1 通配符.............................................................................133

12.3.2 正則.................................................................................133

12.4 使用正則表達式注意事項...............................................133

12.4.1 正則神坑-中文符號............................................................133

12.4.2 grep/egrep 添加別名(CentOS 7 可不配置) .............................................134

12.5 基礎正則.......................................................................134

12.5.1 第 1 個符號【^】 ...............................................................134

12.5.2 第 2 個符號【$】...............................................................134

12.5.3 第 3 個符號【^$】.............................................................135

12.5.4 第 4 個符號【.】................................................................135

12.5.5 第 5 個符號【\】................................................................135

12.5.6 第 6 個符號【*】 ...............................................................137

12.5.7 第 7 個符號【.*】..............................................................137

12.5.8 第 8 個符號【[]】...............................................................139

12.5.9 第 9 個符號【[^]】.............................................................141

12.5.10 小結正則-BRE....................................................................142

12.6 擴展正則.......................................................................142

12.6.1 第 10 個符號【+】.............................................................142

12.6.2 第 11 個符號【|】 .............................................................142

12.6.3 第 12 個符號【()】.............................................................143

12.6.4 第 13 個符號【{}】.............................................................143

12.6.5 第 14 個符號【?】 .............................................................144

12.6.6 ERE 小結...........................................................................144

12.7 基礎正則與擴展正則區別...............................................145

12.7.1 符號不同.........................................................................145

12.7.2 支持的命令不同 .................................................................145

12.8 正則總結-按照功能劃分 .................................................145

12.8.1 基本.................................................................................145

12.8.2 表示重復-連續出現............................................................145

12.9 正則學習資料...................................................................145

第13章 Linux 系統 12 位權限體系...............................................146

13.1 rwx 是啥 ........................................................................146

13.1.1 rwx 含義 ...........................................................................146

13.1.2 linux 如何知道我對某個文件或目錄有什么權限?....................................146

13.2 rwx 對應的數字 及計算方法 rwxr-xr-x...................................................146

13.3 chmod chown 命令的使用.............................................147

13.3.1 chmod 命令......................................................................147

13.3.2 字母形式表示權限 .............................................................147

13.3.3 數字形式表示權限 .............................................................147

13.3.4 chown 命令 ......................................................................148

13.4 對于文件來說 r w x 是什么含義 ...................................148

13.5 對于目錄來說 r w x 是什么含義 ...................................151

13.6 權限錯誤及原因...............................................................153

13.7 linux 系統默認權限控制命令 umask.........................................................153

13.7.1 umask 是什么?...................................................................153

13.7.2 umask 怎么計算?...............................................................153

13.7.3 umask 如何修改?...............................................................153

13.8 網站權限-通過控制權限讓網站安全 .......................................................153

13.8.1 linux 系統默認權限 .............................................................153

13.8.2 網站比較安全的權限 .........................................................154

13.8.3 一臺服務器如何控制安全 .................................................154

13.8.4 網站安全配置權限 .............................................................155

13.9 文件系統屬性(文件隱藏屬性)...................................156

13.9.1 chattr ................................................................................156

13.9.2 lsattr..................................................................................158

13.10 了解特殊權限.................................................................158

13.10.1 suid setuid.......................................................................158

13.10.2 sticky 粘滯位 1777 /tmp 目錄..........................................160

13.10.3 sgid locate.................................................162

13.11 課外:網站的基本結構....................................................163

第14章 用戶管理體系....................................................................164

14.1 讓一個命令或腳本開機自啟動有什么方法?.........................................164

14.1.1 寫入/etc/rc.local .................................................................164

14.1.2 使用 chkconfig 命令管理(CentOS 6.x)................................164

14.2 用戶分類......................................................164

14.2.1 UID .........................................................................164

14.2.2 GID .........................................................................164

14.2.3 root 皇帝 ..............................................................164

14.2.4 虛擬用戶..............................................................164

14.2.5 普通用戶..............................................................165

14.2.6 常用的命令解釋器 .............................................................165

14.3 用戶相關的配置文件.......................................................165

14.3.1 /etc/passwd 用戶的信息....................................................165

14.3.2 /etc/shadow 用戶密碼信息................................................165

14.3.3 /etc/group 用戶的 用戶組信息.........................................165

14.3.4 /etc/gshadow 用戶組密碼信息..........................................166

14.4 與用戶相關的目錄...................................................................166

14.4.1 /etc/skel.................................................................166

14.4.2 命令行中-.* 極度危險.......................................................167

14.5 用戶管理的命令...............................................................167

14.5.1 用戶相關命令 .....................................................................167

14.5.2 如何讓系統更安全 .............................................................168

14.5.3 用戶組相關.........................................................................169

14.5.4 用戶查詢命令 .....................................................................169

14.6 Sudo 臨時讓用戶獲得 root 權限......................................169

14.6.1 su 與 su -區別.......................................................................169

14.6.2 sudo 是什么 .........................................................................169

14.6.3 sudo 怎么用 .........................................................................169

14.7 記錄用戶的操作 行為/日志審計 ...................................170

第15章 LINUX 中高級運維人員必會-定時任務...................................................171

15.1 什么是定時任務...............................................................171

15.2 定時任務分類...................................................................171

15.3 crond 分類：用戶定時任務與系統定時任務 ..........................................171

15.3.1 系統的定時任務 .................................................................171

15.3.2 用戶定時任務 .....................................................................172

15.4 定時任務使用...................................................................172

15.4.1 定時任務依賴的軟件(服務)-是否能用..................................................172

15.4.2 crontab 命令怎么使用.........................................................172

15.4.3 定時任務相關的文件 .........................................................172

15.4.4 定時任務基本格式(分時日月周) .................................173

15.4.5 來一個例子.........................................................................174

15.5 定時任務書寫流程...........................................................174

15.6 總結：9 句箴言................................................................175

15.6.1 定時任務規則之前加注釋 .................................................175

15.6.2 使用腳本替代命令行定時任務 .........................................175

15.6.3 運行腳本一定要用/bin/sh 或 sh........................................175

15.6.4 定時任務中 date 命令%百分號.........................................175

15.6.5 定時任務中-命令或腳本結果(正確及錯誤)定向到黑洞(>/dev/null 2>&1)或追加到文件

中 >>/tmp/oldboy.txt 2>&1 ...................................................................175

15.6.6 避免不必要的程序及命令輸出 .........................................176

15.6.7 打包壓縮使用相對路徑(切到目標目錄的上一級打包目標) .........................................176

15.6.8 定時任務腳本中的程序文件 ,盡量用絕對路徑 ........................................176

15.6.9 系統與命令位置有關的環境變量問題 .......................................................176

15.7 圖片總結定時任務...........................................................178

第16章 Linux 磁盤管理體系.........................................................179

16.1 磁盤知識體系...................................................................179

16.2 磁盤結構.......................................................................179

16.2.1 磁盤外部結構 .....................................................................179

16.2.2 磁盤的內部組成 .................................................................180

16.3 raid .................................................................................180

16.3.1 磁盤陣列.........................................................................180

16.3.2 raid 卡/陣列卡 .....................................................................181

16.3.3 常用 raid 級別.....................................................................181

16.4 磁盤分區.......................................................................181

16.4.1 磁盤分區表.........................................................................181

16.5 磁盤格式化.......................................................................184

16.5.1 fdisk 磁盤分區實踐..............................................................184

16.5.2 parted 磁盤分區實踐 ..........................................................189

16.5.3 fdisk 與 parted......................................................................195

16.5.4 企業案例：java 環境內存不夠用，大量占用 swap ..................................195

16.6 文件系統.......................................................................196

16.6.1 含義.................................................................................196

16.6.2 磁盤文件系統介紹 .............................................................196

16.6.3 分類及區別.........................................................................196

16.6.4 文件系統選擇 .....................................................................196

16.7 磁盤必知必會故障排查...................................................197

16.7.1 文件硬鏈接磁盤滿故障 .....................................................197

16.7.2 磁盤的 inode 滿故障..........................................................198

16.7.3 磁盤的 block 滿故障 ..........................................................199

16.7.4 磁盤滿進程占用故障 .........................................................201

16.8 磁盤相關命令總結...........................................................202

第17章 Linux 系統優化.................................................................205

17.1 添加普通用戶賬號...........................................................205

17.2 關閉 SELinux ...................................................................207

17.2.1 永久關閉 selinux.................................................................207

17.2.2 臨時關閉 selinux.................................................................207

17.3 關閉 iptables(C6)或 Firewalld(C7)防火墻 .....................................208

17.3.1 CentOS 6.x 關閉防火墻........................................................208

17.3.2 CentOS7.x 關閉防火墻 ........................................................208

17.4 如何防止顯示中文亂碼(該優化初期建議不優化，直接強制看英文).......................209

17.5 使用阿里云鏡像做 yum 源 .............................................210

17.5.1 默認國外的 yum 源(軟件倉庫)比較慢，所以換成國內的。....................210

17.5.2 epel 源的安裝 ......................................................................210

17.6 安裝常用軟件...................................................................211

17.7 升級具有典型漏洞的軟件版本.......................................211

17.8 本章小結.......................................................................211

第18章 網絡基礎.............................................................213

18.1 什么是網絡?(重要性---硬件知識)................................213

18.2 網絡通訊名詞概念解釋(重要性---概念清楚)....................................213

18.3 linux 系統中查看路由表信息命令：(兩個) ........................................214

18.4 網絡架構組成(網絡拓撲)...........................................216

18.5 網絡層次模型(OSI7 層模型).....................................216

18.6 OSI7 層模型詳解..............................................................218

18.6.1 應用層.......................................................218

18.6.2 表示層.......................................................218

18.6.3 會話層.......................................................219

18.6.4 傳輸層.......................................................219

18.6.5 數據鏈路層.........................................................................220

18.6.6 網絡層.......................................................221

18.6.7 物理層.......................................................221

18.7 OSI7 層模型概念實際應用..............................................222

18.7.1 OSI 互聯數據包封裝過程....................................................222

18.7.2 OSI 互聯數據包解封裝過程................................................223

18.8 OSI7 層模型做了精簡---TCP/IP 模型(4 層模型)................................224

18.9 TCP/IP 模型(主機層主要協議說明 TCP UDP) ..................................224

18.10 TCP 協議(TCP 報文結構).........................................226

18.11 TCP 三次握手過程 .........................................................227

18.12 TCP 四次揮手 .................................................................228

18.13 三次握手狀態集轉換.....................................................229

18.14 四次揮手狀態集轉換.....................................................230

18.15 網絡知識重要協議原理說明.........................................232

18.16 IP 地址概念說明.............................................................233

18.16.1 IP 轉換.................................................................233

18.16.2 IP 地址的分類 ....................................................................234

18.16.3 IP 子網劃分概念 ................................................................235

18.17 上網原理說明.................................................................236

18.17.1 企業環境訪問互聯網原理 ...............................................236

18.17.2 虛擬網絡環境實現上網原理 ...........................................237

18.18 Linux 系統中路由配置方法...........................................238

18.19 ping 命令使用(禁止 ping icmp--iptables) ...........................................239

18.20 補充擴展.........................................................................239

第19章 附錄:CentOS 6.x VS CentOS 7.x 區別.......................................................240

19.1 整體說明.......................................................................240

19.1.1 系統.................................................................................240

19.1.2 服務軟件.........................................................................240

19.2 詳細操作..................................................................................241

19.3 默認的文件系統..........................................................................241

19.3.1 CentOS 7.5 ........................................................................241

19.3.2 CentOS 6.10 ......................................................................241

19.4 運行級別.......................................................................242

19.4.1 詳細：CentOS 6.x ...............................................................242

19.4.2 詳細：CentOS 7.x ...............................................................242

19.4.3 查看與修改:........................................................................242

19.5 5.內核版本.........................................................................243

19.6 開機自啟動服務...............................................................243

19.6.1 CentOS 6.x .............................................................243

19.6.2 CentOS 7.x .............................................................243

19.7 開啟或關閉服務...............................................................243

19.7.1 CentOS 6.x .............................................................243

19.7.2 CentOS 7.x .............................................................243

19.8 網卡命名.......................................................................244

19.9 普通用戶 uid ....................................................................244

19.10 修改主機名.....................................................................244

19.10.1 CentOS 6.x ...........................................................244

19.10.2 CentOS 7.x ...........................................................244

19.11 修改字符集.....................................................................244

19.11.1 CentOS 6.x ...........................................................244

19.12 軟件包名字.....................................................................245

19.13 管理網卡主要服務： ...................................................245

19.14 防火墻：.........................................................................245

19.15 查看內存 free -h.............................................................245

19.16 /etc/fstab......................................................................245