Pass the RedHat RHCE RH302 Questions and answers with CertsForce

Do the following steps as:

1.vi /etc/hosts.deny

vsftpd:ALL EXCEPT .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.

Outside the LAN means cracker.org. All host on exam on example.com domain and outside domain means cracker.org.

To block the mail coming from cracker.org

1.vi /etc/mail/access

@cracker.rogREJECT

2.service sendmail start | restart

3.chkconfig sendmail on

Do the following steps as:

1.vi /etc/hosts.deny

sshd:ALL EXCEPT .example.com: spawn echo “Loging attempt from %c to %s” | mail –s “Login from denied hosts” root

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/named.conf

zone “example.com” IN {

type master;

file “example.com.zone”;

};

/etc/named.conf file is used to register the zone as well as specify the global option for DNS. There are two types of zone, i. Master, which contains the original data. ii. Slave, backup of master. Here master zone is configured and file name is specified “example.com.zone”, which should be created in /var/named/chroot/var/named/

2.vi /var/named/chroot/var/named/example.com.zone

$TTL 345345

@ IN SOA @ webmaster.example.com.(

101;Serial Number

1H;Refresh Time

1M;Retry Time

1W;Expire Time

1D;Minimum Time to Live

)

@ IN NS 192.100.0.X

www 0 IN A 192.100.0.1

www 0 IN A 192.100.0.2

www 0 IN A 192.100.0.3

www 0 IN A 192.100.0.4

www 0 IN A 192.100.0.5

3.service named start

4.rndc reload

5.chkconfig named on

Zone file should create on /var/named/chroot/var/named. Default Directory Path is specified on /var/named.conf.

$TTLTime To Live, How much seconds cache server stores the information about DNS. And Five Parameters specified Serial Number used by slave to synchronize with master server. Refresh and Retry Time used by slave server. NS is the Name (DNS) server where lookup the domain. A (Associated IP) for particular host. DNS has mechanism to load balance the request from clients. You can verify using hostwww.example.com command.

Do the following steps as:

1.vi /etc/dhcpd.conf

ddns-update-style none;

option routers 192.168.0.1;

option domain-name “example.com”;

option domain-name-servers 192.168.0.254;

default-lease-time 21600;

max-lease-time 43200;

subnet 192.168.0.0 netmask 255.255.255.0

{

range 192.168.0.1 192.168.0.254;

host dns1 {

hardware ethernet 00:50:FC:98:8D:00;

fixed-address 192.168.0.254;

}

host dns2 {

hardware ethernet 00:50:FC:98:8C:00;

fixed-address 192.168.0.253;

}

}

/etc/dhcpd.conf file is used to configure the DHCP. Some global options i.e Gateway, domainname, DNS server specified using option keyword. To assign as static ip from dhcp server, required the mac address of interface.

2.service dhcpd start | restart

Do the following steps as:

1.vi /etc/samba/smb.conf

[global]

netbios name=station?

workgroup=station?

security=user

smb passwd file=/etc/samba/smbpasswd

encrypt passwords=yes

hosts allow= .example.com

[data]

path=/data

public=no

writable=no

write list=john

browsable=yes

2.smbpasswd -a john

3.service smb start

4.chkconfig smb on

/etc/samba/smb.conf. There are some pre-defined section, i. globaluse to define the global options, ii. Printersuse to share the printers, iii. homesuse the share the user’s home directory.

Security=uservalidation by samba username and password. May be there are other users also. To allow certain share to certain user we should use valid users option.

smbpasswdHelps to change user’s smb password. –a option specifies that the username following should be added to the local smbpasswd file.

If any valid users option is not specified, then all samba users can access the shared data. By Default shared permission is on writable=no means read only sharing. Write list option is used to allow write access on shared directory to certain users or group members.

Do the following steps as:

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

<VirtualHost 192.100.0.1>

ServerNamewww.abc.com

DocumentRoot /var/www/abc/

<Directory /var/www/abc>

AllowOverrideauthconfig

</Directory>

DirectoryIndexindex.html

ServerAdminwebmaster@abc.com

ErrorLog logs/error_abc.logs

CustomLog logs/custom_abc.logs common

</VirtualHost>

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

3.vi /var/www/abc/.htaccess

AuthName“Only to Authorized Users”

AuthTypebasic

AuthUserFile/etc/httpd/conf/mypasswd

requirevalid-user

htpasswd –c /etc/httpd/conf/mypasswd user5

htpasswd –m /etc/httpd/conf/mypasswd user6

chgrp apache /etc/httpd/conf/mypasswd

chmod g+r /etc/httpd/conf/mypasswd

service httpd restart

chkconfig httpd on

AllowOverride Authconfig is used to specify which and how much configuration can be overridden by directory specific .htaccess files.

One of the most common tasks performed in users’ .htaccess files is adding authorization. Typically, a user will setup authorization for directories that hold sensitive information with a configuration.

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.Open the Browser either firefox or links

2.Type :http://localhost:631

3.Click on Manage Printer

4.Click on Add Printer

5.Type Queue name like stationx and click on continue

6.Type Device type or printing Protocol: i.e Internet printing Protocol

7.Click on Continue

8.Type Device URL: ipp://server1.example.com/printers/printerx

9.Click on Continue

10.Select RAW Model printer

11.Click on Continue

12.Test by sending the printing job

Do the following steps as:

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.