S

Samba, 516–544. See also Samba clients; Samba Server Configuration utility; Samba servers

client configuration for, 520–523

configuring with shares, 543–544

defined, 813

exam topics on, 495

installing, 517–518

interoperability with Linux/Unix, 519

joining domains, 533

lab questions and answers, 549–551, 553–556

managing users, 534–535

misspellings of variables, 533

overview, 516–517

prerequisite skills for, 46

self test and answers, 548–549, 552

server configuration for, 523–533

setting up SELinux support for, 518, 713–714

starting on Linux boot, 518

testing changes to /etc/samba/smb. conf, 542

two-minute drill, 546–547

Windows and, 494, 519

Samba clients, 520–523

checking file and print services, 520–521

configuring print services for, 523

mounting shared directories during login, 521–523

types of, 520

Samba Server Configuration utility, 536–541

configuring users, 539–540

creating public access shares, 540–541

modifying global settings with, 537–538

setting share permissions, 539

starting, 517–518

using, 537

Samba servers, 523–533

Active Directory configurations for, 525–527

adding sticky bit to permission values, 542

configuring users, 533, 539–540

directory sharing on Microsoft domains, 525

editing /etc/samba/smb.conf file, 523–524

joining domains, 533

looking up variables for, 529

modifying global settings, 524–529

public access shares for, 540–541

setting share permissions for, 539

share setting for, 529–533

sharing home directories, 535–536

using Windows passwords and usernames, 529, 533

Samba Users dialog (Samba Server Configuration utility), 541

Sample Exam 1, 768–781

Installation and Configuration portion, 776–781

Troubleshooting and System Maintenance portion, 768–776

Sample Exam 2, 784–782

Installation and Configuration portion, 793–798

Troubleshooting and System Maintenance portion, 784–793

sample kickstart file, 248–251, 253

SATA (serial ATA) drives

adding, 423–424

defined, 814

scientific method, 728–733

scripts

adding Kickstart Configurator installation, 260

disabling xinetd configuration, 618

/etc/rc.sysinit, 293

executing with permissions, 28–29

importance of shell programming with, 27

kernel configuration, 396–400

runlevel 5 kill and start, 163

startx, 666

searching for files, 20–21

Secure Shell (SSH) package, 620–626

about, 614

advantages of, 623–625

configuring SSH server, 625–626

encrypted communications and, 621–622

exam's focus on, 615

lab questions and answers, 641–642, 644–647

overview, 620–621

private keys, 621

self test and answers, 640–641, 643

SSH client configuration, 626

SSH services on Windows, 626

summarized, 637

two-minute drill, 638

utilities generating keys, 623

secure virtual hosts, 468–469, 813

security, 30–34, 692–726. See also authentication; passwords; permissions

allowing and denying files, 48

at and cron daemons, 359–360

Apache, 456–458, 460

basic network, 47–48

checking to see if system cracked, 274

configuring iptables command, 698–700

file permissions, 30–31, 289–290

firewalls and packet filtering, 697–703

implementing with SELinux, 209, 210, 706–716

kernel configuration options for, 407

lab questions and answers, 721–722, 724–726

maintaining firewall configurations in iptables file, 700

multiple partitions for, 102

NAT and, 48, 703–706

NIS, 47

overview, 58, 692–693

PAM, 306–308, 311–313

password, 277

preventing ping of death, 383

protecting network computers, 693

reducing NFS risks, 506

RHCE exam requirements for, 692

risks for NFS, 505–506

securing ports, 48

Security Level Configuration tool, 701–703

self test and answers, 720–721, 723–724

sendmail, 595–596

Setroubleshoot browser, 715–716

shadow passwords, 33

Squid Proxy Server options for, 482

SUID and SGID permissions, 32–33

summarized, 717

tcp_wrappers and packet, 693–697

two-minute drill, 718–719

used-based Apache, 460–461

users, groups, and masks, 31–32

vsFTP server, 513–514

xinetd and, 47

yum command for updating, 242

Security Enhanced Linux. See SELinux

Security Level Configuration tool, 701–703

illustrated, 701

modes for, 701

SELinux Management Tool vs., 709

setting up SELinux in Permissive mode, 707

Security tab (Samba Server Configuration utility), 537, 538

sed (stream editor), 23–24

selecting e-mail systems, 599–603

alternatives command for, 599

e-mail clients, 600–601

reading mail messages, 50, 601

system-switch-mail command to switch systems, 600

testing results of e-mail service, 600–601, 602–603

working with mail group "alias" lists, 602

self test and answers

Apache and Squid, 486–487, 488–489

booting, 175–176, 180–181

DNS, 579–580, 581

e-mail, 605–606, 608–609

filesystem administration, 212–213, 215–216

hardware and installation, 133–134, 140–141

kernels, 433–434, 437–438

network file sharing services, 548–549, 552

other networking services, 640–641, 643

package management, 263–264, 267–268

prerequisite skills, 61–62, 64–65

security, 720–721, 723–724

system administration tools, 367–368, 371–372

troubleshooting, 761–762, 764–765

user administration, 321–322, 324–325

X Window System, 684–685, 687

SELinux (Security Enhanced Linux), 706–716. See also SELinux Management Tool

about, 81, 706–707

added to Red Hat Exam Prep guide, 81, 184, 208

configuring during first boot, 122–123

CUPS protection disabled when configuring, 354

at daemon and, 359

defined, 813

development of, 209

diagnosing network services problems due to, 759

disabling during exam troubleshooting, 330

e-mail interference by, 586

exam configuration tips, 708

experimenting in Permissive mode, 707

file contexts for, 706

lab questions and answers, 721–722, 724–726

logging service protection disabled by, 360

making NFS work with, 502

manually configuring, 708–709

problems for NTP service with, 635

security implemented with, 210

Setroubleshoot browser, 715–716

setting up support for Samba, 518, 713–714

settings for cron daemon, 357

status configurations using /etc/ sysconfig/selinux, 707

support for vsFTP servers, 512–513

trouble opening SELinux Management Tool when disabled, 83

using SELinux Management Tool, 83, 709–715

SELinux Management Tool, 709–715

about, 708

advantages over Security Level Configuration tool, 709

configuring Boolean operations, 710–714

file labeling options, 714–715

illustrated, 710, 715

SELinux User options (SELinux Management Tool), 715

sendmail, 592–597

accepting mail from unresolved domains, 595

alternatives to, 586

basic operation of, 594–597

configuring and securing, 595–596

defined, 814

key configuration files for, 592–593

lab questions, 606–607, 609–611

macros for sendmail.mc file, 594

prerequisite skills for, 45

restarting modified, 596

RPM packages for, 588–589

selecting with alternatives command, 599

self test and answers, 605–606, 608–609

SMTP used to send mail, 587–588

summarized, 603

troubleshooting, 596–597

two-minute drill, 604

using system-switch-mail command to switch systems, 600

serial ATA. See SATA drives

serial number errors in DNS, 574

server certificates, 466

Server Settings (Samba Server Configuration utility), 537, 538

servers. See also DNS servers; network installation servers; Samba servers; servers; Squid

Apache Web, 447, 449–450, 456–466, 474–475

caching-only name, 561, 563–565, 801

components of mail, 587

configuring kickstart, 246–247

defined, 814

DHCP, 86–87, 627, 628–631, 633

forwarding-only name, 561, 565–566

FTP and vsFTP, 85–86, 94, 95, 512–515

HTTP, 83–85, 94, 95

network installation, 81, 86–87

NFS, 81–83, 494–509

NTP time, 634–637

RAM requirements for Linux, 7

Samba, 523–533

securing host servers with tcp_wrappers, 694–696

slave name, 561, 565

SSH, 625–626

storage space required for file, 103–104

time-efficient method for installation from remote, 92–95

using multiple X.org, 659–660

X.org, 658–669

X Window System, 651–653

Servers package group, 115–118

service accounts, 274

service command, 35

Service Configuration tool, 168–169

service httpd reload command, 448

Sessions dialog, 523

Sessions utility, 667

set command, 29

setenforce command, 708

setfacl command, 814

Setroubleshoot browser, 715–716

SGID (set group ID) bit

controlling group ownership with, 303–305

defined, 303, 814

inheritance of group ID from, 302

using SGID permissions, 32–33

Shadow Password Suite, 33–34, 814

share settings for Samba servers, 529–533

shared directories. See also network file sharing services

activating NFS directories at appropriate runlevels, 501

adding with NFS Server Configuration tool, 499–502

creating, 302–303

mounting from NFS client computer, 509–512

reviewing and reading NFS, 205–206

Samba, 520–523, 535–536

sharing Samba directory on Microsoft domains, 525

sharing files with Apache, 458–459

shells. See also bash shell

changing file and directory permissions for, 289–290

checking PATH, 28

configuration files for, 287–290

defined, 26

environment variables for, 29

/etc/bashrc file for, 287

/etc/profile file for, 288–289

hidden files added to user shell configuration, 290

managing data streams in, 29–30

prerequisite skills for, 26–30, 58

programming with scripts, 27

script execution and permissions, 28–29

variables and parameters for, 27–28

wildcards in, 25

showmount command, 814

Simple Mail Transfer Protocol (SMTP), 587–588, 804

single quote ('), 595

single-user mode, 814

slave name servers, 561, 565

smbd daemon, 520

smbmount command, 522

smbpasswd command, 533, 534, 535, 814

smbumount command, 522

SMP computers, 75

SMTP (Simple Mail Transfer Protocol), 587–588, 804

SOA (Start of Authority), 814–815

soft limits for disk quotas, 295, 815

soft mounting option for NFS clients, 511–512

software RAID. See RAID

software updates. See updating

sort command, 23

sorting files, 23

sound card testing, 125

source RPMs

building from tar archive, 230

changing compile options for, 231–232

creating custom, 230, 232–233

defined, 815

directory structure of /usr/src/ redhat, 231

installing, 230

kernel, 394–396

locating, 394

required customization RPMs for kernels, 395–396

RHEL 5, 54

spam protection, 714

spamassassin directory, 592–593

spec files, 815

SQL (Structured Query Language), 815

Squid, 476–483

about, 444, 476–477

advantages of, 481

configuring /etc/squid/squid.conf file, 478–480

defined, 815

/etc/sysconfig/squid file, 478

key files and directories, 477

lab questions and answers, 487, 489–491

localizing options for, 480–481

options in SELinux Management Tool for, 714

proxy server configuration for, 482–483

security settings for, 482

self test and answers, 486–487, 488–489

starting on reboot, 477–478

summarized, 484

two-minute drill, 485

srm.conf file, 451

SRPMs. See source RPMs

SSH. See Secure Shell package

ssl.conf file, 450

standard error (stderr), 29

standard groups, 301–302

standard input (stdin), 29

standard linux rescue environment, 738–740

standard ouput (stdout), 29, 30

stanzas

about, 529–533

changing GRUB's default, 390

Start of Authority (SOA), 814–815

starting

X Window, 659

Squid, 477–478

Startup Programs tab (Sessions dialog), 523

startx command for X.org servers, 666–669

stateless protocol of NFS, 502–503

static IP addresses, 39

sticky bit for Samba permissions, 542

stream editor (sed), 23–24

Structured Query Language (SQL), 815

su command, 34, 284

subscriptions to Red Hat Network, 53

sudo command, 34, 284–285

SUID bit, 522, 815

SUID permissions, 32–33

superusers, 34, 815

swap partitions

making with parted utility, 195–196

setting up fdisk, 190–191

troubleshooting, 747

swap space, 104–105, 747, 815

switchdesk command, 680–681, 746

switches, 19

symbolically linked NFS files, 503

sync command, 740

syntax of virtual host containers, 470

syslog.conf log configuration file, 361

syslogd (system log daemon), 360–362

system administration tools, 330–374

about, 330

cron and at for automating administration, 354–360

CUPS, 341–354

exam objectives for, 330

lab questions and answers, 368–370, 372–374

network configuration, 331–340

self test and answers, 367–368, 371–372

summarized, 364

two-minute drill, 365–366

working with system logs, 360–364

system configuration files, 169–172

GUI tools for, 171–172

non-network /etc/sysconfig files, 170

system log daemon (syslogd), 360–362

system logs, 360–364

configuration file for syslogd, 360–362

inspecting, 364

logging daemons in RHEL, 360

managing, 38, 362

standard Red Hat, 363

system-config-* commands, 815

system-config-bind command, 561

system-config-display command, 651

system-config-network command, 334–336

system-config-samba command, 536–537

system-config-securitylevel command, 701