RedHat RH302 RHCE (Redhat Certified Engineer) Exam Practice Test

Do the following steps as:

1.vi /etc/xinetd.d/telnet

service telnet {

only_from=192.168.0.0/24

access_times=09:00-17:00

}

2.chkconf telnet on

3.service xinetd restart

xinetd based services can manage by specifying host and time parameters. Only_from means connection allowed network, remaining hosts explicitly deny. access_times specify when service is available.

At exam Lab example.com domain resides on 172.24.0.0/16 Network and my133t.org resides on 172.25.0.0/16 Network.

1.vi /etc/squid/squid.conf

#detault:

http_port8080

#Recommended minimum configuration:

# Near the src acl src section

acl allownet src 172.24.0.0/255.255.0.0

acl denynet src 172.25.0.0/255.255.0.0

#Default:

# http_access deny all

#Under Herehttp_access allow allownet

http_access deny denynet

2.service squid start

3.chkconfig squid on

squid is a proxy caching server, using squid we can share the internet, block the internet, to certain network. First we should define the port for squid, the standard port for squid is 3128. We can run squid on different port by specifying http_port portnumber.

Do the following steps as:

1.vi /etc/named.conf

acl localnet { 192.168.0.0/24; };

options {

allow-query { localnet; };

};

2.service named restart | start

allow-query is a global option on /etc/named.conf, specifies an address match list of hosts allowed to query this server. If this option is not set, any host can query the server.

Do the following steps as:

1.vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com

or

1.vi /etc/hosts.deny

sshd:ALL

2.vi /etc/hosts.allow

sshd:.example.com

We can secure the services using tcp_wrappers. There are main two files, /etc/hosts.allow and /etc/hosts.deny.

There will be three stage access checking

- Is access explicitly permitted? Means permitted from /etc/hosts.allow?

- Otherwise, Is access explicitly denied? Means denied from /etc/hosts.deny?

- Otherwise, by default permit access if neither condition matched.

To deny the services we can configure /etc/hosts.deny file using ALL and EXCEPT operation. Pattern of /etc/hosts.allow and /etc/hosts.deny file is:

Demon_list:client_list:options

In Client list can be either domain name or IP address.

Do the following steps as:

1.vi /etc/squid/squid.conf

#detault:

http_port8080

#Recommended minimum configuration:

# Near the src acl src section

acl allownet src 192.168.0.0/255.255.255.0

acl denynet src 192.168.1.0/255.255.255.0

#Default:

# http_access deny all

#Under Herehttp_access allow allownet

http_access deny denynet

2.service squid start

3.chkconfig squid on

squid is a proxy caching server, using squid we can share the internet, block the internet, to certain network. First we should define the port for squid, the standard port for squid is 3128. We can run squid on different port by specifying http_port portnumber.

To block or allow the Internet access to hosts, we should create the acl (Access Control List). In this file we can specify only the IP address.

Example: acl aclname src IP/NetmaskAfter creating acl we can block or allow the internet to specified acl.

http_access allow | deny alcname

Do the following steps as:

1.vi /etc/named.conf

options {

forwarders { 192.168.22.250; };

forward only;

};

2. service named start | restart

Caching-only name server forwards a request to another name server or to the root name servers in orders to determine the authoritative name server for the resolution. Once resolution has taken place, the caching-only name server stores the resolved information in a cache for the designated time to live period.

Do the following steps as:

1.vi /etc/httpd/conf/httpd.conf

<VirtualHost 192.168.0.?>

ServerNamestation?.example.com

DocumentRoot /var/www/station?

DirectoryIndexindex.html

ServerAdminwebmaster@example.com

</VirtualHost>

2.Create the directory and index page on specified path. (Index page can download fromftp://server1.example.comat exam time)

3.service httpd start|restart

4.chkconfig httpd on

Do the following steps as:

1.vi /etc/httpd/conf.d/ssl.conf

<VirtualHost 192.100.0.2>

ServerNamewww.rhce.com

DocumentRoot /var/www/rhce

DirectoryIndex index.html index.htm

ServerAdminwebmaster@rhce.com

SSLEngine on

SSLCertificateFile/etc/httpd/conf/ssl.crt/server.crt

SSLCertificateKeyFile/etc/httpd/conf/ssl.key/server.key

</VirtualHost>

2.cd /etc/httpd/conf

3.make testcert

4.Create the directory and index page on specified path. (Index page can download fromftp://server1.example.comat exam time)

5.service httpd start|restart

6.chkconfig httpd on

Apache can provide encrypted communications using SSL (Secure Socket Layer). To make use of encrypted communication, a client must request to https protocol, which is uses port 443. For HTTPS protocol required the certificate file and key file.

Do the following steps as:

1.vi /etc/mail/local-host-names

example.com

2.vi /etc/mail/sendmail.mc

dnl # DEAMON_OPTIONS(`Port=smtp,Addr=127.0.0.1,Name=MTA`)dnl

3.m4 /etc/mail/sendmail.mc >/etc/mail/sendmail.cf

4.vi /etc/mail/access

RELAY

example.comRELAY

5.service sendmail start | restart

6.chkconfig dovecot on

7.vi /etc/dovecot.conf

protocols = pop3 pop3s

8.service dovecot start | restart

9.chkconfig dovecot on

/etc/mail/local-host-names file contains the aliases to hostname. Mail server program reads the /etc/mail/sendmail.cf. To change the configuration on mail server, we should edit the /etc/mail/sendmail.mc file and should generate the sendmail.cf using m4 command.

By default sendmail server allows to connect to local host only. So we should edit the /etc/mail/sendmail.mc file to allow connect to other hosts.

By default sendmail server will not forward mail. we should specify on /etc/mail/access to relay or to block mail coming from domain or network or individual email address.

By default dovecot service start only the imap protocol. To start pop protocol with dovecot, we should write in /etc/dovecot.conf file.

Think while Problems occurred on booting System on Runlevel 5 (X Window).

/tmp is full or not

Quota is already reached

Video card or resolution or monitor is misconfigured.

xfs service is running or not.

Do These:

1.df –h /tmp/tmp is full remove the unnecessary file

quota usernameif quota is already reached remove unnecessary file from home directory.

Boot the System in runlevel 3.you can pass the Kernel Argument from boot loader.

Use command: system-config-displayIt will display a dialog to configure the monitor, Video card, resolution etc.

Set the Default Runlevel 5 in /etc/inittab

id:5:initdefault:

6.Reboot the System you will get the GUI login Screen.

1. vi /etc/resolv.conf

Write : nameserver 192.168.0.254

This is boot related problem. There will be same questions repeated two times but problem is different.

First When you restart the system you will get the Error:

File Not Found

mount: error 15 mounting ext3

mount: error 2 mounting none

switchroot: mount failed: 22

umount /initrd/dev/: 2

Kernel Panic: no syncing: Attempted to kill init !

This error occurred in your system before showing welcome redhat linux. That means problem in grub boot loader.

Restart the System

Check the grub boot loader configuration by pressing e shortcut key.

You will see like:

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root= / rhgb quiet

initrd /initrd-2.6.9-5.EL.img

OR

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/root rhgb quiet

initrd /initrd-2.6.9-5.EL.img

Then Edit Boot loader to make like

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/ rhgb quiet

initrd /initrd-2.6.9-5.EL.img

Check all lines and edit as same as above. Press b to boot the system

After booting the system you should correct the /etc/grub.conf file.

If still you are getting Error likeFile not found, it seems that either kernel file or initrd file is missing. To troubleshoot with these problem, boot the system on rescue mode.

linux rescue

chroot /mnt/sysimage

Check the files on /boot, if not available install the kernel package from ftp or nfs server

Create the initrd image file on boot using: mkinitrd initrd-2.6.9-5.EL.img `uname –r`

When root unable to login into the system think:

Is password correct?

Is account expired?

Is terminal Blocked?

Do these Steps:

Boot the System on Single user mode.

Change the password

Check the account expire date by using chage –l root command.

If account is expired, set net expire date: chage –E “NEVER” root

Check the file /etc/securettyWhich file blocked to root login from certain terminal.

If terminal is deleted or commented write new or uncomment.

Reboot the system and login as a root.

Do the following steps as:

1.First check the size of Logical Volume: lvdisplay /dev/vo/myvol

2.Increase the Size of Logical Volume: lvextend -L+121M /dev/vo/myvol

3.Make Available the size on online: ext2online /dev/vo/myvol

4.Verify the Size of Logical Volume: lvdisplay /dev/vo/myvol

5.Verify that the size comes in online or not: df -h

We can extend the size of logical Volume using the lvextend command. As well as to decrease the size of Logical Volume, use the lvresize command. In LVM v2 we can extend the size of Logical Volume without unmount as well as we can bring the size of Logical Volume on online using ext2online command.

This is boot related problem. There will be same questions repeated two times but problem is different.

First When you restart the system you will get the Error:

mount: error 15 mounting ext3

mount: error 2 mounting none

switchroot: mount failed: 22

umount /initrd/dev/: 2

Kernel Panic: no syncing: Attempted to kill init !

This error occurred in your system before showing welcome redhat linux. That means problem in grub boot loader.

Restart the System

Check the grub boot loader configuration by pressing e shortcut key.

You will see like:

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root= / rhgb quiet

initrd /initrd-2.6.9-5.EL.img

OR

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/root rhgb quiet

initrd /initrd-2.6.9-5.EL.img

Then Edit Boot loader to make like

root (hd0,0)

kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/ rhgb quiet

initrd /initrd-2.6.9-5.EL.img

Check all lines and edit as same as above. Press b to boot the system

After booting the system you should correct the /etc/grub.conf file.

Maintenance mode also known as emergency mode. System boots on emergency mode when file system error occurred. It is due to unknown partition, bad filesystem specified in /etc/fstab. To slove follow the steps

Give the Root password

fdisk –lVerify the Number of parations.

Identify the Root partition, e2label /dev/hda1, e2label /dev/hda2…..

Remount the root partation on rw mode: mount –o remount,defaults /dev/hda6 /

vi /etc/fstab

Correct all partitions, mount point, mount options, file system etc.

6.Press ctrl+d

Do the following steps as:

Use fdisk /dev/hdaTo create new partition.

Type nFor New partitions

It will ask for Logical or Primary Partitions. Press l for logical.

It will ask for the Starting Cylinder: Use the Default by pressing Enter Key.

Type the Size: +100MYou can Specify either Last cylinder of Size here.

Press P to verify the partitions lists and remember the partitions name.

Press w to write on partitions table.

Either Reboot or use partprobe command.

Use mkfs –t ext3 /dev/hda?

Or

mke2fs –j /dev/hda? To create ext3 filesystem.

vi /etc/fstab

Write:

/dev/hda?/dataext3defaults0 0

11. Verify by mounting on current Sessions also:

mount /dev/hda? /data

Do the following steps as:

Use fdisk /dev/hdaTo create new partition.

Type nFor New partitions

It will ask for Logical or Primary Partitions. Press l for logical.

It will ask for the Starting Cylinder: Use the Default by pressing Enter Key.

Type the Size: +100MYou can Specify either Last cylinder of Size here.

Press P to verify the partitions lists and remember the partitions name.

Press w to write on partitions table.

Either Reboot or use partprobe command.

Use mkfs –t ext3 /dev/hda? Where ? is your partition number

Or

mke2fs –j /dev/hda? To create ext3 filesystem.

mkdir /mnt/neo

vi /etc/fstab

Write:

/dev/hda?/mnt/neoext3defaults1 2

Verify by mounting on current Sessions also:

mount /dev/hda? /mnt/neo

We know that every files/directories are owned by certain user and group. And Permissions are defines to owner user, owner group and other.

-rwxr-x---Full permission to owner user, read and write to owner group and no permission to others.

According to question: We should give the full permission to user user1 without changing the previous permission.

ACL (Access Control List), in ext3 file system we can give permission to certain user and certain group without changing previous permission. But that partition should mount using acl option. Follow the steps

vi /etc/fstab

/dev/hda14/dataext3defaults,acl0 1

Either Reboot or use: mount –o remount /data

setfacl –m u:user1:rwx /data

Verify using: getfacl /data

Do the following steps as:

echo “1” >/proc/sys/net/ipv4/ip_forward

vi /etc/sysctl.conf

net.ipv4.ip_forward=1

/proc is the virtual filesystem, containing the information about the running kernel. To change the parameter of running kernel you should modify on /proc. From Next reboot the system, kernel will take the value from /etc/sysctl.conf.

Do the following steps as:

Use fdisk /dev/hdaTo create new partition.

Type nFor New partitions

It will ask for Logical or Primary Partitions. Press l for logical.

It will ask for the Starting Cylinder: Use the Default by pressing Enter Key.

Type the Size: +100MYou can Specify either Last cylinder of Size here.

Press P to verify the partitions lists and remember the partitions name.

Press w to write on partitions table.

Either Reboot or use partprobe command.

Use mkfs –t ext3 /dev/hda? Where ? is your partition number

Or

mke2fs –j /dev/hda? To create ext3 filesystem.

mkdir /mnt/neo

vi /etc/fstab

Write:

/dev/hda?/mnt/neoext3defaults1 2

Verify by mounting on current Sessions also:

mount /dev/hda? /mnt/neo

In Network problem thinks to check:

IP Configuration: use ifconfig command either IP is assigned to interface or not?

Default Gateway is set or not?

Hostname is set or not?

Routing problem is there?

Device Driver Module is loaded or not?

Device is activated or not?

Check In this way:

use ifconfig command and identify which IP is assigned or not.

cat /etc/sysconfig/networkWhat, What is written here. Actually here are these parameters.

NETWORKING=yes or no

GATEWAY=x.x.x.x

HOSTNAME=?

NISDOMAIN=?

Correct the file

Use vi /etc/sysconfig/network-scirpts/ifcfg-eth0 and check the proper options

DEVICE=eth0

ONBOOT=yes

BOOTPROTO=static

IPADDR=x.x.x.x

NETMAKS=x.x.x.x

GATEWAY=x.x.x.x

Use service network restart or start command

To automatically mount at boot time we use the /etc/fstab file. Because /etc/rc.d/rc.sysinit file reads and mount all file system specified in /etc/fstab. To mount Network Sharing Files also use the /etc/fstab but filesystem is nfs.

vi /etc/fstab

192.168.0.254:/data/commonnfsdefaults0 0

reboot the system.

Do the following steps as:

1.First check the size of Logical Volume: lvdisplay /dev/vo/myvol

2.Make sure that the filesystem is in a consistent state before reducing:

# fsck –f /dev/vo/myvol

3.Now reduce the filesystem by 200MB.

# resize2fs /dev/vo/myvol 200M

4.It is now possible to reduce the logical volume.

#lvreduce /dev/vo/myvol –L 200M

4.Verify the Size of Logical Volume: lvdisplay /dev/vo/myvol

5.Verify that the size comes in online or not: df -h

Very Tricky question from redhat. Actually question is giving scenario to you to implement quota to neo user. You should apply the quota to neo user on /home that neo user shouldn’t occupied space more than 70K.

1.vi /etc/fstab

LABEL=/home/homeext3defaults,usrquota0 0To enable the quota on filesystem you should mount the filesystem with usrquota for user quota and grpquota for group quota.

2.touch /home/aquota.userCreating blank quota database file.

3.mount -o remount /homeRemounting the /home with updated mount options. You can verify that /home is mounted with usrquota options or not using mount command.

4.quotacheck -u /homeInitialization the quota on /home

5.edquota –u neo /homeQuota Policy editor

See the snapshot

Disk quotas for user neo (uid 500):

Filesystem blocks soft hard inodes soft hard

/dev/mapper/vo-myvol 2 30 70 1 0 0

Can you set the hard limit 70 and soft limit as you think like 30.

Verify using the repquota /home command.

Do the following steps as:

hostname station?.example.comThis will set the host name only for current session. To set hostname permanently.

vi /etc/sysconfig/network

HOSTNAME=station?.example.com

service network restart

Do the following steps as:

1.vi /etc/sysconfing/network

NETWORKING=yes

HOSTNAME=station?.example.com

GATEWAY=192.168.0.254

2.service network restart

Or

1.vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

ONBOOT=yes

BOOTPROTO=static

IPADDR=X.X.X.X

NETMASK=X.X.X.X

GATEWAY=192.168.0.254

2.ifdown eth0

3.ifup eth0

Do the following steps as:

useradd eric

passwd eric

vi /etc/passwd

eric:x:505:505::/home/eric:/sbin/nologin

Which shell or program should start at login time is specified in /etc/passwd file. By default Redhat Enterprise Linux assigns the /bin/bash shell to the users. To deny the interactive login, you should write /sbin/nologin or /bin/false instead of login shell.

Do the following steps as:

1. use the authconfig or system-config-authentication

2. Select the [*] USE NIS

3. Type the NIS Domain: rhce.com

4. Type Server 192.168.0.254 then click on next and ok

5. You will get a ok message.

6. vi /etc/auto.master and write at the end of file

/home/stationx /etc/auto.home --timeout=60

7. vi /etc/auto.home and write

*-rw,soft,intr192.168.0.254:/home/stationx/&

Note: please specify your station number in the place of x.

8. Service autofs restart

9. Login as the rhce1 or rhce2 or rhce3 on another terminal will be

Success.

According to question, rhce.com domain is already configured. We have to make a client of rhce.com domain and automatically mount the home directory on every client. To make a member of domain, we use the autheconfig or system-config-authentication command. There are lots of authentication server i.e NIS, LDAB, SMB etc. NIS is a RPC related Services, no need to configure the DNS, we should specify the NIS server address.

Here Automount feature is available. When user tried to login, home directory will automatically mount. The automount service reads the configuration from /etc/auto.master file.

On /etc/auto.master file we specified the mount point the configuration file for mount point.

Do the following steps as:

Login as a root user

cat >schedule.txt

30 05 * * * /bin/echo “Hello”

3. crontab –u david schedule.txt

4. service crond restart

The cron system is essentially a smart alarm clock. When the alarm sounds, Linux runs the commands of your choice automatically. You can set the alarm clock to run at all sorts of regular time intervals. Alternatively, the at system allows you to run the command of your choice once, at a specified time in the future.

Red Hat configured the cron daemon, crond. By default, it checks a series of directories for jobs to run, every minute of every hour of every day. The crond checks the /var/spool/cron directory for jobs by user. It also checks for scheduled jobs for the computer under /etc/crontab and in the /etc/cron.d directory.

Here is the format of a line in crontab. Each of these columns is explained in more detail:

#minute, hour, day of month, month, day of week, command

*        *     *             *      *            command

Entries in a crontab Command Line

Field

Value

Minute

0-59

Hour

Based on a 24-hour clock; for example, 23 = 11 p.m.

Day of month

1-31

Month

1-12, or jan, feb, mar, etc.

Day of week

0-7; where 0 and 7 are both Sunday; or sun, mon, tue, etc.

Command

The command you want to run

Note: Examiner will provide you the Installation startup CD. And here mentioned size may vary see on the exam paper.

1.Insert the CD on CD-ROM and start the system.

2.In Boot: Prompt typelinux askmethod

3. It will display the Language, keyboard selection.

4. It will ask you for the installation method.

5. Select the HTTP from the list

6. It will ask the IP Address, Net mask, Gateway and Name Server. Select Use

Dynamic IP Configuration: because DHCP Server will be configured in your exam lab.

7. It will ask for the Web site name and Redhat Enterprise Linux Directory.

Specify the HTTP Server: 192.168.0.254

Directory: rhel4Because Default Directory for http is /var/www/html

8. After Connecting to the HTTP Server Installation start. Go upto the partition screen by selecting the different Options.

9. Create the partition According to the Question because Size and what-what partition should you create at installation time is specified in your question

10. Then select the MBR Options, time zone and go upto package selections.

It is another Most Important Time of installation. Due to the time limit, you should be

care about the installation packages. At Exam time you these packages are enough.

X-Window System

GNOME Desktop

(these two packages are generally not required)

Administration Tools.

System Tools

Windows File Server

FTP Servers

Mail Servers

Web Servers

Network Servers

Editors

Text Based Internet

Server Configuration Tools

Printing Supports

When installation will complete, your system will reboot. Jump for another Question.

Do the following steps as:

1.chmod 770 /archive

2.Verify using : ls –ld /archive

Preview should be like:

drwxrwx--- 2 root sysuser 4096 Mar 16 18:08 /archive

To change the permission on directory we use the chmod command. According to the question that only the owner user (root) and group member (sysuser) can fully access the directory so: chmod 770 /archive

Do the following steps as:

1.echo “1” >/proc/sys/net/ipv4/ip_forward

2.vi /etc/sysctl.conf

net.ipv4.ip_forward = 1

If you want to use the Linux System as a Router to make communication between different networks, you need enable the IP forwarding. To enable on running session just set value 1 to /proc/sys/net/ipv4/ip_forward. As well as automatically turn on the IP forwarding features on next boot set on /etc/sysctl.conf file.

We can change the permission of file/directory either character symbol method or numeric method.

Permission:

r-Read

w-Write

x-Execute

Permission Category

u- Owner User

g- Owner Group

o- Others

Operators

+Add the Permissions

-Remove the Permissions

=Assigns the Permissions

Numeric Method:

4Read

2Write

1Execute

Total: 7, total for owner user, owner group member and for others : 777

chmod u+rwx /data

chmod g+rwx /data

chmod o-rwx /data

or

chmod 770 /data

Verify the /data : ls –ld /data

You will get drwxrwx---

Do the following steps as:

1. Insert the CD on CD-ROM and start the system.

2. In Boot: Prompt typelinux askmethod

3. It will display the language, keyboard selection.

4. It will ask you for the installation method.

5. Select the NFS Image from the list

6. It will ask the IP Address, Net mask, Gateway and Name Server. Select Use

Dynamic IP Configuration: because DHCP Server will be configured in your exam lab.

7. It will ask for the NFS Server Name and Redhat Enterprise Linux Directory.

Specify the NFS Server: 192.168.0.254

Directory: /var/ftp/pub

8. After Connecting to the NFS Server Installation start in GUI. Go up to the partition screen by selecting the different Options.

9. Create the partition According to the Question because Size and what-what partition should you create at installation time is specified in your question

10.Create the two RAID partitions having equal size of remaining all free space.

11.Click on RAID button

12.Type mount point /data

13.Select RAID Level 0

14.Click on ok

15. Then select the MBR Options, time zone and go upto package selections.

It is another Most Important Time of installation. Due to the time limit, you should care about the installation packages. At Exam time you these packages are enough.

X-Window System

GNOME Desktop

(these two packages are generally not required)

Administration Tools.

System Tools

Windows File Server

FTP Servers

Mail Servers

Web Servers

Network Servers

Editors

Text Based Internet

Server Configuration Tools

Printing Supports

When installation will complete, your system will reboot. Jump for another Question.

Do the following steps as:

1.chmod g+s /data

2.Verify using: ls -ld /data

Permission should be like:

drwxrws--- 2 root sysadmin 4096 Mar 16 18:08 /data

If SGID bit is set on directory then who every users creates the files on directory group owner automatically the owner of parent directory.

To set the SGID bit: chmod g+s directory

To Remove the SGID bit: chmod g-s directory

Do the following steps as:

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

acl localnet { 192.168.0.0/24; };

options {

allow-query { localnet; };

};

2.service named restart | start

allow-query is a global option on/var/named/chroot/etc/named.conf, specifies an address match list of hosts allowed to query this server. If this option is not set, any host can query the server.

Do the following steps as:

1. vi /etc/mail/virtusertable

accountmanager@jeff

2. service sendmail restart

Do the following steps as:

1.vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com

or

1.vi /etc/hosts.deny

sshd:ALL

2.vi /etc/hosts.allow

sshd:.example.com

We can secure the services using tcp_wrappers. There are main two files, /etc/hosts.allow and /etc/hosts.deny.

There will be three stage access checking

- Is access explicitly permitted? Means permitted from /etc/hosts.allow?

- Otherwise, Is access explicitly denied? Means denied from /etc/hosts.deny?

- Otherwise, by default permit access if neither condition matched.

To deny the services we can configure /etc/hosts.deny file using ALL and EXCEPT operation. Pattern of /etc/hosts.allow and /etc/hosts.deny file is:

Demon_list:client_list:options

In Client list can be either domain name or IP address.

Do the following steps as:

1.vi /etc/httpd/conf/httpd.conf

ServerNamestation?.example.com

DocumentRoot /var/www/station?

DirectoryIndexindex.html

ServerAdminwebmaster@example.com

2.Create the directory and index page on specified path. (Index page can download fromftp://server1.example.comat exam time)

Check the SELinux context of index page , should like this:

-rw-r--r-- root root system_u:object_r:httpd_sys_content_t /var/www/html/index.html

If SELinux Context is mismatched, use the restorecon –R /var command

3.service httpd start|restart

4.chkconfig httpd on

Do the following steps as:

ftpftp.server1.example.com

Download thewww.html

Check the SELinux context of index page , should like this:

-rw-r--r-- root root system_u:object_r:httpd_sys_content_t /var/www/html/index.html

If SELinux Context is mismatched, use the restorecon –R /var command

move the downloaded file into /var/www/html

Rename the file into index.html

Check using linkshttp://stationx.example.com

/var/www/html is the default directory for httpd service. Index.html is the default directory index. To set the default page without configuring virtualhost copy the file as a index.html in /var/www/html.

Do the following steps as:

1.vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com

or

1.vi /etc/hosts.deny

sshd:ALL

2.vi /etc/hosts.allow

sshd:.example.com

We can secure the services using tcp_wrappers. There are main two files, /etc/hosts.allow and /etc/hosts.deny.

There will be three stage access checking

- Is access explicitly permitted? Means permitted from /etc/hosts.allow?

- Otherwise, Is access explicitly denied? Means denied from /etc/hosts.deny?

- Otherwise, by default permit access if neither condition matched.

To deny the services we can configure /etc/hosts.deny file using ALL and EXCEPT operation. Pattern of /etc/hosts.allow and /etc/hosts.deny file is:

Demon_list:client_list:options

In Client list can be either domain name or IP address.

Do the following steps as:

1.vi /etc/exports

/data*.example.com(rw,sync)

2.service nfs start

3.service portmap restart

4.chkconfig nfs on

5.chkconfig portmap on

In Linux to share the data we use the /etc/exports file. Pattern is:

Pathclient(permission)

Shared Directory Path, Client can be single host or domain name or ip address. Permission should specify without space with client lists in parentheses.

Do the following steps as:

1.vi /etc/hosts.deny

sshd: 192.168.0. EXCEPT 192.168.0.4

We can secure the services using tcp_wrappers. There are main two files, /etc/hosts.allow and /etc/hosts.deny.

There will be three stage access checking

-Is access explicitly permitted? Means permitted from /etc/hosts.allow?

- Otherwise, Is access explicitly denied? Means denied from /etc/hosts.deny?

- Otherwise, by default permit access if neither condition matched.

To deny the services we can configure /etc/hosts.deny file using ALL and EXCEPT operation. Pattern of /etc/hosts.allow and /etc/hosts.deny file is:

Demon_list:client_list:options

In Client list can be either domain name or IP address.

Do the following steps as:

vi /etc/mail/virtusertable

@cracker.orgeric

service sendmail restart

/etc/mail/virtusertable file is used to send the mail coming for virtual user to real user. According to question, all mail to cracker.org should get by eric user so

@cracker.orgeric : Which sends all mail of cracker.org to eric user.

Steps of Creating LVM:

Physical Disk1

Physical Disk2

Physical Disk3

Physical Volume

Volume Group

Logical Volume 1

Logical Volume 2

Logical Volume 3

1.pvcreate /dev/hda8 /dev/hda9 /dev/hda10

pvdisplay command is used to display the information of physical volume.

2.vgceate test0 /dev/hda8 /dev/hda9 /dev/hda10

vgdisplay command is used to display the information of Volume Group.

3.lvcreate –L 250M –n testvolume1 test0

lvdisplay command is used to display the information of Logical Volume.

4.lvcreate –L 250M –n testvolume2 test0

5.mkfs –t ext3 /dev/test0/testvolume1

6.mkfs –t ext3 /dev/test0/testvolume2

7.mkdir /lvtest1

8.mkdir /lvtest2

9.mount /dev/test0/testvolume1 /lvtest1

10.mount /dev/test0/testvolume2 /lvtest2

11.vi /etc/fstab

/dev/test0/testvolume2/lvtest2ext3defaults0 0

/dev/test0/testvolume1/lvtest1ext3defaults0 0

To create the LVM( Logical Volume Manager) we required the disks having ‘8e’ Linux LVM type. First we should create the physical Volume, then we can create the Volume group from disks belongs to physical Volume. lvcreate command is used to create the logical volume on volume group. We can specify the size of logical volume with –L option and name with -n option.

Do the following steps as:

useradd user1

useradd user2

useradd user3

passwd user1

passwd user2

passwd user3

We create the user using useradd command and we change the password of user using passwd command. If you want to set the blank password use: passwd -d username.

Do the following steps as:

Login as a root user

cat >schedule.txt

30 05 * * * /bin/echo “Hello”

3. crontab –u david schedule.txt

4. service crond restart

The cron system is essentially a smart alarm clock. When the alarm sounds, Linux runs the commands of your choice automatically. You can set the alarm clock to run at all sorts of regular time intervals. Alternatively, the at system allows you to run the command of your choice once, at a specified time in the future.

Red Hat configured the cron daemon, crond. By default, it checks a series of directories for jobs to run, every minute of every hour of every day. The crond checks the /var/spool/cron directory for jobs by user. It also checks for scheduled jobs for the computer under /etc/crontab and in the /etc/cron.d directory.

Here is the format of a line in crontab. Each of these columns is explained in more detail:

#minute, hour, day of month, month, day of week, command

*        *     *             *      *            command

Entries in a crontab Command Line

Field

Value

Minute

0-59

Hour

Based on a 24-hour clock; for example, 23 = 11 p.m.

Day of month

1-31

Month

1-12, or jan, feb, mar, etc.

Day of week

0-7; where 0 and 7 are both Sunday; or sun, mon, tue, etc.

Command

The command you want to run

Do the following steps as:

1.chmod g+s /archive

2.Verify using: ls -ld /archive

Permission should be like:

drwxrws--- 2 root sysuser 4096 Mar 16 18:08 /archive

If SGID bit is set on directory then who every users creates the files on directory group owner automatically the owner of parent directory.

To set the SGID bit: chmod g+s directory

To Remove the SGID bit: chmod g-s directory