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Phil's Brain Melters: Linux Administration & Security
n/a
232
Computer Networking
Not Applicable
03/26/2013

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Cards

Term
To which of the following ports would you expect the httpd web server to bind?
Definition
80
Term
To which of the following ports could you expect the firefox web client to bind?
Definition
42351
Term
Which of the following is a conventional IPv4 address?
Definition
192.168.0.1
Term
In Linux, what is the term for a process duplicating itself, thereby creating a new process?
Definition
forking
Term
Which IP address connects directly back to the same machine?
Definition
127.0.0.1
Term
Which of the following commands would immediately start the vsftpd daemon?
Definition
service vsftpd start
Term
Which of the following commands would cause the vsftpd service to be started automatically at bootup?
Definition
chkconfig vsftpd on
Term
Which directory contains the Red Hat Enterprise Linux service scripts?
Definition
/etc/rc.d/init.d/
Term
Which of the following commands would list the runlevel startup configuration for the vsftpd service?
Definition
chkconfig --list vsftpd
Term
The vsftpd daemon is provided by what Red Hat Enterprise Linux package?
Definition
vsftpd
Term
Which of the following is the primary configuration file for vsftpd?
Definition
/etc/vsftpd/vsftpd.conf
Term
In the default Red Hat Enterprise Linux configuration, which of the following types of FTP users are allowed to connect?
Definition
Both A and B
Term
In the default Red Hat Enterprise Linux configuration, which of the following types of FTP users are chrooted?
Definition
Anonymous Users
Term
If anonymous users are chrooted, to which directory are the chrooted?
Definition
/var/ftp
Term
After editing the main configuration file, which of the following commands could be run to cause the changes to take effect?
Definition
service vsftpd restart
Term
Which of the following is not a SELinux state?
Definition
paranoid
Term
What is the name of the default Red Hat Enterprise Linux SELinux policy?
Definition
targeted
Term
Which file establishes the default SELinux state upon bootup?
Definition
None of the above
Term
Which of the following processes would you expect to be most constrained by an active Red Hat Enterprise Linux default SELinux policy?
Definition
httpd
Term
Which of the following command lines could be used to most directly determine the current SELinux state?
Definition
getenforce
Term
Which of the following commands can be used to immediately change the SELinux state of a machine?
Definition
setenforce
Term
Which of the following commands would view the SELinux domain of the process with process ID 3452?
Definition
ps -Z 3452
Term
Which of the following command would display the SELinux security context of the file /etc/passwd?
Definition
ls -Z /etc/passwd
Term
What file would you examine in order to see logs of SELinux violations?
Definition
/var/log/messages
Term
Which of the following commands would cause the file foo to inherit the SELinux security context of the file bam? (2 answers)
Definition
chcon -R bam foo

chcon --reference=bam foo
Term
Which is the common term for the process by which hostnames are converted to IP addresses?
Definition
DNS
Term
Which of the following files are potentially consulted on a client attempting to convert a hostname into an IP address?
Definition
/etc/resolv.conf
/etc/hosts
Term
Which of the following is not a feature of the Domain Name database?
Definition
Typically, end clients must recursively consult multiple nameservers in order to obtain an answer.
Term
What is the root node of the Domain Name hierarchy called?
Definition
"."
Term
What is the term for the type of Domain Name query which is typically made between an end client and a nameserver?
Definition
A recursive query
Term
Assuming that all nameservers involved have an empty cache, how many transactions between nameservers (not end clients) are required to resolve the hostname www.library.ncsu.edu?
Definition
4
Term
Assume that all nameservers involved perform caching, but that all caches are initially empty. An end client resolves www.sales.widgets.org, and then resolves www.developer.widgets.org. How many transactions between nameservers (not end clients) are required to resolve the hostname?
Definition
2
Term
Which of the following is not considered a top level domain?
Definition
.www
Term
Typically, which component of a Linux end client is responsible for Domain Name lookups?
Definition
the libresolv.so library
Term
What is the term for the type of Domain Name query which is typically made between one nameserver and another?
Definition
an iterative query
Term
What is most likely the cause of the problem?

[root@station ~]# service named start
named: unrecognized service
Definition
The bind package is not installed.
Term
Which of the following is the key configuration file associated with Red Hat Enterprise Linux's Domain Name server?
Definition
/etc/named.conf
Term
What is the default Red Hat Enterprise Linux log file for the Domain Name daemon?
Definition
/var/log/messages
Term
Which of the following commands would be used to query the nameserver ns.example.com about the host www.widgets.org?
Definition
host www.widgets.org ns.example.com
Term
How many root level nameservers are there?
Definition
10-20
Term
Which of the following packages contains database zone files?
Definition
caching-nameserver
Term
Where would you expect to find the file named.ca? if it was being specified as a zone file in /etc/named.conf
Definition
/var/named by default
Term
zone "." IN {
type hint;
file "named.ca";

what type of name server is this specifying?
Definition
caching-only
Term
zone "example.com" {
type master;
file "example.com.zone";

what type of server is this named.conf stanza specifying?
Definition
a master nameserver which holds/edits its own database files
Term
zone "widgets.org" {
type slave;
masters { 10.4.8.12; };
file "widgets.org.zone";

what type of nameserver is this stanza specifying?
Definition
a slave nameserver which gets its database updates from a master nameserver for a zone/domain
Term
what is a common mistake when configuring resource records as far as typos are concerned?
Definition
not specifying the zone type
Term
What is incorrect about the A record defining station1.example.com?
Definition
it should be ending with a "."
Term
what character can be used to mark comment lines in zone files?
Definition
a semicolon ";"
Term
Can CNAME records refer directly to IP addresses?
Definition
no they are for aliasing and require another name in the "RDATA" field
Term
can a CNAME record refer to another hostname specified as a hostname as its RDATA?
Definition
no
Term
what basic pieces of info do SOA records define?
Definition
what nameserver is being talked about and where you can reach the person in charge of the nameserver via email
as well as a timestamp of the last edit that was made to the zone
Term
in the SOA record on a zone file, what is the format of the serial number which indicates when changes have been made last?
Definition
YYYYMMDDNN, where NN allows up to 99 changes per day
Term
which command will list the SOA record for a zone?
Definition
host -a example.com
Term
What hostname is associated with the reverse lookup of the IP address 192.168.0.3?
Definition
3.0.168.192.in-addr.arpa.
Term
Which of the following command lines could be used to perform a reverse lookup of the IP address 192.168.0.3?
Definition
host 192.168.0.3

host 3.0.168.192.in-addr.arpa
Term
what is special about the format of the name of a reverse lookup zone?
Definition
the subnet it is servicing is in reverse order before the ".IN-ADDR.ARPA"
Term
Are A records allowed in reverse lookup zones?
Definition
no.
Term
are multiple pointer records allows for a single IP address?
Definition
no
Term
Domains can be split up into multiple zones but zones cannot be split up into multiple...
Definition
domains
Term
Which of the following is the only type of zone which a caching only nameserver capable of performing internet lookups is required to implement?
Definition
hint
Term
What is the name of the domain which servers as the root of the DNS hierarchy?
Definition
. ("dot")
Term
Which of the following is the term for a nameserver which maintains its own DNS database?
Definition
master
Term
Which of the following files on a client can directly influence hostname resolution?
Definition
/etc/hosts
/etc/resolv.conf
Term
What is the name of the Red Hat Enterprise Linux service which provides DNS?
Definition
named
Term
Which of the following packages are required to implement a caching only nameserver without modifying any files?
Definition
bind
bind-utils (usually already installed)
caching-nameserver (part of bind package in RHEL6)
Term
Which of the following applications rely on the libresolv library to perform DNS lookups?
Definition
ping
nautilus
curl
ssh
Term
Which of the following files is the default log file for the named daemon?
Definition
/var/log/messages
Term
Which of the following commands could be used to query the nameserver at 192.168.0.254 about the host www.redhat.com?
Definition
host www.redhat.com 192.168.0.254
Term
Which of the following problems exist in the SOA record? (refer to handout for workbook 3)
Definition
The contact email address is not properly formated.
Term
What is the probable role of the ns.crunchyseeds.com nameserver with regards to the sugarpuffs.com domain? (refer to handout)
Definition
The host probably acts as a slave nameserver.
Term
What is incorrect about the crunchyseeds.com zone in the top level configuration file? (refer to handout)
Definition
The zone type is set to slave, but no master nameserver is referenced.
The zone type is set to slave, but a filename is also specified.
Term
What is wrong with the line defining the ldap.sugarpuffs.com CNAME? (refer to handout)
Definition
The hostname in the origin field, as written, should end in a dot (".").
Term
Which of the following hosts are properly configured to be members of the sugarpuffs.com zone? (refer to handout)
Definition
ftp.sugarpuffs.com

smtp.sugarpuffs.com
Term
What is wrong with the line defining sales.sugarpuffs.com? (refer to handout)
Definition
The record uses an incorrect commenting syntax.


The origin field does not use a fully qualified hostname.
Term
What is incorrect about the reverse lookup zone definition in the main configuration file? (refer to handout)
Definition
The zone name is incorrectly constructed for a reverse lookup zone for the 192.168.0.0/24 subnet.
Term
What required record type is missing from the reverse lookup zone database file?
(refer to handout)
Definition
NS
Term
What can be said about qa.sugarpuffs.com? (refer to handout)
Definition
The domain is a member of the sugarpuffs.com domain, but not the sugarpuffs.com zone.
Term
Which of the following is incorrect about the 192.168.10.0/24 reverse lookup zone? (refer to handout)
Definition
There are redundant entries for the origin field 10, which is not allowed.
Term
Where would you expect to find the file sugarpuffs.com.zone? (refer to handout)
Definition
/var/named/sugarpuffs.com.zone
Term
Which best describes the purpose of Samba?
Definition
Implements windows-style file sharing and name-resolution protocols
Term
Samba is actually a collection of which two daemons?
Definition
smbd and nmbd
Term
What package(s) are needed for samba client support?
Definition
samba-common and samba-clients
Term
What Red Hat Enterprise Linux 4 service controls the Samba server?
Definition
smb
Term
Which of the following is the most secure way to access a samba share without being prompted for a password?
Definition
smbclient -A file //server/share
Term
What package(s) are needed for samba server support?
Definition
samba-common and samba
Term
Which of the following would display a list of shares on a Samba server?
Definition
smbclient -L server
Term
What smbclient command can be used to retrieve files from a Samba share?
Definition
get
Term
Which smbclient option forces an anonymous (password-less) connection?
Definition
-N
Term
What smbclient command can be used to upload files to a Samba share?
Definition
put
Term
True of False: Spaces are allowed within Samba configuration options
Definition
True
Term
Which configuration option controls how Samba authenticates users?
Definition
security
Term
Why does Samba require a separate smbpasswd file?
Definition
To support Windows-style authentication
Term
Where is samba's configuration file located?
Definition
/etc/samba/smb.conf
Term
What is the default authentication source for Samba?
Definition
The local Linux userbase

Its own smbpasswd file
Term
What command can be used to check the syntax of Samba's configuration file?
Definition
testparm
Term
What is Samba's default behavior with regard to printers?
Definition
All printers are shared
Term
Which of the following systems will be able to access the server?

hosts allow 192.168.0.
hosts deny 192.168.0.5
Definition
192.168.0.5
192.168.0.200
Term
Where does the Samba server log to?
Definition
/var/log/samba/.log
Term
Which of the following authentication sources can Samba not use directly?

A SQL database of user information

Another Samba server

A Windows NT PDC

Locally stored user and password information

An Active Directory DC
Definition
A SQL database of user information
Term
Which directive controls whether or not a share will be treated as a printer?
Definition
printable
Term
What does the public option control?
Definition
whether or not anonymous access to the server is permitted
Term
Which option controls the directory that a share makes accessible?
Definition
path
Term
What command can be used to resolve a NETBIOS name to an IP?
Definition
nmblookup
Term
What is the correct way to begin a share definition?
Definition
[sharename]
Term
What is the correct way to end a share definition?
Definition
Share definitions do not use an explicit closing tag
Term
browseable = no
public = no
read only = yes
valid users = @admin, @web
write list = @admin

joe: web,users
jane: admin,web,users
john: users

What level of access will joe have?
Definition
read-only access
Term
browseable = no
public = no
read only = yes
valid users = @admin, @web
write list = @admin

joe: web,users
jane: admin,web,users
john: users

What level of access will jane have?
Definition
read and write access
Term
browseable = no
public = no
read only = yes
valid users = @admin, @web
write list = @admin

joe: web,users
jane: admin,web,users
john: users

What level of access will john have?
Definition
no access
Term
browseable = no
public = no
read only = yes
valid users = @admin, @web
write list = @admin

joe: web,users
jane: admin,web,users
john: users

True or False: This share will be omitted from the server's share list
Definition
True
Term
What command can be used to list open ports on a machine?
Definition
netstat -tunap
Term
In "netstat -tunap", what does the P switch do?
Definition
displays PID of owner process of connection
Term
IP routes data to/from ... and operates at level..
Definition
computers
level 3
Term
TCP/UDP routes data to/from...and operates at level...
Definition
applications
level 4
Term
what is a socket?
Definition
a combination of an IP address and a port number
Term
servers always bind to __________ ports
Definition
well known
Term
FTP uses port
Definition
20/21 TCP
Term
SSH uses port
Definition
22 TCP
Term
SMTP uses port
Definition
25 TCP
Term
DNS uses port
Definition
53 UDP
Term
HTTP uses port
Definition
80 TCP
Term
POP3 uses port
Definition
110 TCP
Term
imap uses port
Definition
143 TCP
Term
pop3s uses port
Definition
995 TCP
Term
imaps uses port
Definition
993 TCP
Term
https uses port
Definition
443 TCP
Term
ms-ds uses port
Definition
445 TCP
Term
well known ports are aka
Definition
privileged ports
Term
the 3 process binding methods are
Definition
loopback
explicit ip
any ip
Term
the two most important TCP session states are
Definition
listen and established
Term
the process of LISTEN-ing TCP/UDP process duplicating itself to deal w/ a client is called:
Definition
forking
Term
the steps to configuring a network service are:
Definition
Install
Start w/ service cmd
Enable boot time loading w/ chkconfig
Configure
Test
Secure
Term
RPM uses _________, while YUM uses _______
Definition
filename, package name
Term
what is chrooting?
Definition
the process of changing the root directory of a daemon/user
Term
every process is put into an SELinux ...
Definition
domain
Term
every resource is put into an SELinux...
Definition
context
Term
the 3 SELinux states are...
Definition
enforcing
permissive
disabled
Term
RHEL 6's default webserver is...
Definition
apache
Term
HTTP code 200 indicates...
Definition
success
Term
http code 301 indicates
Definition
authorization required
Term
HTTP code 403 indicates...
Definition
access denied
Term
http code 404 indicates
Definition
file not found
Term
http code 501 indicates
Definition
internal server error
Term
the 3 httpd.conf sections are...
Definition
global
main
virtual
Term
the 4 configurable scopes within apache are...
Definition
directory
location
files
virtualhost
Term
what options can be specified within the 4 configuration scopes of apache?
Definition
options
ACLs
overrides
Term
the two types of virtual hosts in apache are
Definition
IP based
name based
Term
why is one IP address allowed to resolve to multiple virtual web servers?
Definition
HTTP 1.1 also requires a hostname on top of the server IP
if no hostname specified, first vhost is used
Term
squid's configuration file is...
Definition
/etc/squid/squid.conf
Term
squid binds to port .... by default
Definition
3128
Term
squid's access log is...
Definition
/var/log/squid/access.log
Term
the 3 types of nameservers used with BIND are...
Definition
master
slave
caching only
Term
an authoritative nameserver is one which can...
Definition
provide direct knowledge of a zone member
Term
what does the name daemon do with problematic zone files?
Definition
skips them
Term
reverse lookup zones contain...
Definition
PTR records
Term
NFS enables...
Definition
unix based computers to share a common directory
Term
to packages required to install NFS are...
Definition
nfs-utils
rpc-bind
Term
the file used to designate a directory as an NFS share is...
Definition
/etc/exports
Term
when applying NFS configs, it is better to _________ rather than ___________
Definition
reload rather than restart
Term
the basic DHCP acquisition sequence is ...
Definition
Discover
Offer
Request
Acknowledge
Term
DHCP's config file is...
Definition
/etc/dhcpd.conf
Term
what file does DHCP use as it's log file?
Definition
/var/log/messages
Term
the 3 samba packages are...
Definition
samba-clients
samba-common
samba
Term
the 2 samba daemons are...
and are started by...
Definition
smbd: handles core of SMB protocol
nmbd: implements WINS nameservice

started by service smb start
Term
the format which samba shares are accessed is called
Definition
universal naming convention
Term
the command used to connect to samba shares is called
Definition
smbclient
Term
to connect to a samba share, users require
Definition
a samba username/password
Term
smbclient -L shows what
Definition
the neighborhood of shares around a server
Term
smbclient -U specifies
Definition
an alternate username to sign into a samba share with
Term
smbclient -N means
Definition
do not ask for password while accessing samba share if possible
Term
smbclient -A specifies
Definition
to use an "auth_file" instead of logging into a share at the command line
Term
the samba config file is...
Definition
/etc/samba/smb.conf
Term
manuals for samba can be found in
Definition
/usr/share/doc/samba-*/htmldocs
Term
in the event of a samba ACL conflict, will allow or deny take precedence?
Definition
allow
Term
the load_printers option set to yes will share...
Definition
all print queueus in /etc/printcap
Term
the log file for samba is...
Definition
/var/log/samba/smb.log
Term
samba usernames and passwords are stored in...
Definition
/etc/samba/smbpasswd
Term
what command can be used to audit the syntax of a configuration file?
Definition
testparm
Term
when a server gets a request for a share it...
Definition
asks if the share is a sharename
asks if the share is a user's home dir
asks if the share is a print queue
Term
what command resolves netbios names
Definition
nmblookup
Term
what file stores which processes use which ports
Definition
/etc/services
Term
what file is used to filter ip connections
Definition
/etc/sysconfig/iptables
Term
what file can be used to set the SELinux state
Definition
/etc/sysconfig/selinux
Term
what command displays the SELinux state of a machine
Definition
getenforce
Term
what does setsebool do?
Definition
sets boolean values related to selinux
Term
what does restorecon do?
Definition
restores selinux context of all files in a specified path
Term
what does chcon do?
Definition
updates context of a file by referencing a known working context
Term
ps/ls -Z performs what function?
Definition
will list SELinux info as a switch for each of these commands
Term
raw SElinux log messages are stored in..
Definition
/var/log/audit/audit.log
Term
apache's document root is...
Definition
/var/www/html
Term
apache's config file is...
Definition
/etc/httpd/conf/httpd.conf
Term
what file stores successful and unsuccessful connection logs on apache?
Definition
/var/log/httpd/access_log
Term
what file only displays unsuccessful connection attempts on apache?
Definition
/var/log/httpd/error_log
Term
what directory is searched for additional apache config files?
Definition
/etc/httpd/conf.d/*.conf
Term
squid's config file is...
Definition
/etc/squid/squid.conf
Term
squid's access log is...
Definition
/var/log/squid/access.log
Term
what two files are consulted for DNS name resolution?
Definition
/etc/hosts
/etc/resolv.conf
Term
the config file for the BIND/DNS service is...
Definition
/etc/named.conf
Term
the config file for caching only nameservers is...
Definition
/etc/named.caching-nameserver.conf
Term
default location for zone files is...
Definition
/var/named
Term
where does the name daemon store logs
Definition
/var/log/messages
Term
In Red Hat Enterprise Linux 5, which of the following packages provides the Apache web server?
Definition
httpd
Term
After migrating the contents of a web site from one operating system to another, web clients, when viewing the URL http://localhost/zsh.txt, are displaying raw html instead of a formatted page: What is the simplest solution to the problem?
Definition
Rename the file zsh.html.
Term
In what file are all web requests from clients ("hits") logged?
Definition
/var/log/httpd/access_log
Term
If, when running service httpd start, the webserver fails to start, what file might contain helpful debugging messages?
Definition
/var/log/httpd/error_log
Term
Apache's dynamically loaded modules are conventionally found in what directory?
Definition
/usr/lib/httpd/modules
Term
Which directory serves as the ServerRoot directory (i.e., the directory used as the base for all relative file references in the configuration file) ?
Definition
/etc/httpd
Term
Which of the following directives can be used to defend against memory leaks and other instabilities in poorly written libraries and CGI scripts?
Definition
MaxRequestsPerChild
Term
Which of the following best describes the default Apache server model?
Definition
The server uses a pre-forking model, whereby clients are distributed amongst a dynamic pool of pre-existing daemons.
Term
Which of the following lines would cause the web server to bind to port 8080 on the loopback address?
Definition
Listen 127.0.0.1:8080
Term
The apache manual states that %h is used to log the remote hostname or IP address. Yet, even using this parameter, and administrator finds a log file logs using IP addresses instead. Which of the following configurations would allow client hostnames to be logged?
Definition
HostnameLookups On
Term
Which of the following directives would have the same end effect as cd /var/www/html/data; ln -s ../images images ?
Definition
Alias /data/images/ /var/www/html/images/
Term
After editing an Apache configuration file, what should be done for changes to take effect?
Definition
service httpd restart
Term
Which of the following is not a legitimate keyword for opening an Apache scoping container?

files
directory
location
virtual host
Definition
they're all legitimate.
Term
Which of the following protocols does the Apache webserver use to associate an IP-based virtual host with a client request?
Definition
TCP/IP
Term
Which of the following protocols does the Apache webserver use to associate a Name-based virtual host with a client request?
Definition
HTTP
Term
Which of the following directives would you not be able to override using an Apache virtual host?
Definition
KeepAliveTimeout
Term
Which best describes the purpose of NFS?
Definition
To allow a directory to be shared between systems
Term
Upon what other service does NFS depend?
Definition
portmap
Term
Which of the following are reliable ways to reload NFS's exports list?
Definition
service nfs stop, followed by service nfs start

exportfs -r
Term
Red Hat Enterprise Linux 4 defaults to which of the following options when exporting NFS directories?
Definition
synchronous
Term
What does the root_squash option control?
Definition
Whether or not the root user on the client system is given root access to nfs shares from this machine
Term
Which directive has the opposite effect as root_squash ?
Definition
no_root_squash
Term
Which package provides the NFS server daemons?
Definition
nfs-utils
Term
Which best describes the purpose of DHCP?
Definition
Automatic assignment of IP addresses and other options
Term
What is the sequence of client/server messages used to establish a new lease?
Definition
DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK
Term
What configuration option defines the list of IPs that will be leased out to clients?
Definition
range
Term
What configuration option precedes a non-IP setting to be handed out to clients?
Definition
option
Term
Which of the following commands can be used to observe the DHCP daemon's lease history?
Definition
cat /var/lib/dhcp/dhcpd.leases
Term
What command starts the dhcpd daemon?
Definition
service dhcpd start
Term
True or false: It is usually undesirable to have more than one dhcp server on the same physical network.
Definition
True
Term
True of false: A DHCP server is necessary for managing networks with more than a few clients.
Definition
False
Term
To which file does the dhcpd daemon log?
Definition
/var/log/messages
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