102-500 Sample Questions Answers

LIMIT

FROM

WHERE

IF

It is the process ID of the echo command.

It is the process ID of the current shell.

It is the process ID of the last command executed.

It is the process ID of the last command which has been placed in the background.

for

loop

until

while

It contains the welcome message that is displayed after login.

It contains security profiles defining which users are allowed to log in.

It contains environment variables that are set when a user logs in.

It contains default application profiles for users that run an application for the first time.

env

set

env -a

echo $ENV

A continuous stream of numbers increasing in increments of 10 until stopped.

The numbers 1 through 10 with one number per line.

The numbers 0 through 9 with one number per line.

The number 10 to standard output.

ptrace

strace

debug

lsof

nessus

export LANGUAGE=“pt”

export LC_MESSAGES=“pt”

export UI_MESSAGES=“pt”

export MESSAGE=“pt”

export ALL_MESSAGES=“pt”

getargs

lsenv

ls

env

lsshell

The field is not changed during the transport of a package.

The field is transmitted within a hop-by-hop extension header.

Each router forwarding the packet increases the field’s value.

Each router forwarding the packet decreases the field’s value.

For multicast packages, the field’s value is always 1.

SMTP

POP3

NTP

IMAP

LDAP

result: 6 5 4

result: 1 2 3 4 5 6

result: 3 4 5 6 2 1

result: 6 5 4 3 2 1

result: 3 2 1

Manage and adjust bandwidth used by TCP services.

Bind a network service to a TCP port.

Encapsulate TCP messages in IP packets.

Add SSL support to plain text TCP services.

Limit access to a network service.

It must be sent by any SSH client in addition to a user key in order to identify the client's host.

It provides the server's identity information to connecting SSH clients.

It is the root key by which all user SSH keys must be signed.

It authenticates any user that logs into a remote machine from the key's host.

It is used by system services like cron, syslog or a backup job to automatically connect to remote hosts.

find /usr -uid 0 -perm +4000

find -user root +mode +s /usr

find -type suid -username root -d /usr

find /usr -ls \*s\* -u root

find /usr -suid -perm +4000

/etc/ssh/sshd_config

/etc/ssh/ssh

/etc/ssh/client

/etc/ssh/ssh_config

/etc/ssh/ssh_client

local7

mail

advanced

postmaster

remote

The skew in time between the system clock and the hardware clock.

The skew in time between the system clock and the reference clock.

Changes in the time zone of the current computer's location.

Adjustments needed to support Daylight Saving Time.

Because the conversion of Unix timestamps to local time relies on the time zone configuration.

Because the time zone is saved as part of the modification times of files and cannot be changed after a file is created.

Because the environment variables LANG and LC_MESSAGES are, by default, set according to the time zone.

Because NTP chooses servers nearby based on the configured time zone.

rotatelog

striplog

syslogd --rotate

logrotate

logger

lpq

mailq

mlq

sendmail –l

groupdel

groupmod

groups

groupedit

Every user may have their own crontab.

Changing a crontab requires a reload/restart of the cron daemon.

The cron daemon reloads crontab files automatically when necessary.

hourly is the same as "0 * * * *".

A cron daemon must run for each existing crontab.

In the database file /etc/crontab.db which is shared by all users.

As individual per-user files within /var/spool/cron.

As individual per-user files in /etc/cron.user.d.

In the .crontab file in the user's home directory.

In the file /var/cron/user-crontab which is shared by all users.

The user bob is removed from the system's user database.

The user bob's home directory is removed.

The locate database is updated to drop files owned by bob.

All files owned by bob are remove from all mounted filesystems.

In case bob was the last member of a group, that group is deleted.

Add the specific user to /etc/at.allow file.

Add the specific user to [deny] section in the /etc/atd.conf file.

Add the specific user to /etc/at.deny file.

Add the specific user to nojobs group.

Run the following: atd --deny [user].

usermod

passwd

chattr

chage

chsh

cat UTC > /etc/timezone

ln -s /usr/share/zoneinfo/UTC /etc/localtime

date --timezone=UTC

mv /usr/timezone/UTC /etc

The number of days since January 1, 1970 after which the user's account will no longer be accessible.

The number of days since January 1, 1970 after which the password can change.

The number of days since January 1, 1970 since the password was last changed.

The maximum number of days during which a password is valid.

The number of days of inactivity after a password has expired before the account is locked.

127.0.0.0/8

10.0.0.0/8

169.255.0.0/16

172.16.0.0/12

192.168.0.0/16

substitute

nameserver

search

lookup

method

The local routing information may be corrupted and must be re-validated using a routing protocol.

One of the routers in the routing table is not available which causes the automatic router failure detection mechanism (ARF-D) to wait for a timeout.

There may accidentally be more than one default router in which case a default router election has to be done on the network in order to choose one router as the default.

DNS resolution may not be working as route by default tries to resolve names of routers and destinations and may run into a timeout.

With IPv6, the TCP port numbers of most services have changed.

IPv6 no longer supports broadcast addresses.

IPv4 addresses can be used without any change with IPv6.

IPv6 no longer supports multicast addresses.

For IPv6, UDP and TCP have been replaced by the Rapid Transmission Protocol RTP.

The default route is always used first. When the default route is not available more specific routes are tried.

When a default route is set, all other routes are disabled until the default route is deleted.

The default route is only used if there is not a more specific route to a destination host or network.

Without a default route, no network communication even in directly attached networks is possible.

resolv

dns

remote

files

hosts

route del default

ifconfig unset default

netstat -r default

ip route del default

sysctl ipv4.default_gw=0

/etc/X11/xdm/Xsetup

/etc/X11/xdm.conf

/etc/X11/xdm/Defaults

/etc/X11/defaults.conf

xkb

atkb

GOK

xOSK

It reads text displayed on the screen to blind or visually impaired people.

It reads the parameters of the attached monitors and creates an appropriate X11 configuration.

It displays lines and markers to help people use speed reading techniques.

It manages and displays files that contain e-books.

To assist users who have difficulty holding down multiple keys at once

To prevent repeated input of a single character if the key is held down

To ignore brief keystrokes according to a specified time limit

To repeat the input of a single character