Firewalls And Network Security Chapters 4 - 7

Front 1

Linux has a kernel-level packet filter called _____.

Back 1

IPchains

Front 2

In an IP packet header, the _____ address is the address of the computer or device that is to receive the packet.

Back 2

destination

Front 3

In an IP packet header, the _____ header length describes the length of the header in 32-bit words and is a 4-bit value.

Back 3

Internet

Front 4

The default value of the Internet header length in an IP packet header is __.

Back 4

20

Front 5

The size of the time to live field in an IP packet header is _.

Back 5

8

Front 6

The size of the flag field in an IP packet header is _.

Back 6

3

Front 7

The maximum length of an IP packet that can be defined in the total length field is ___,___.

Back 7

165,535

Front 8

The number in the header's _____ field tells a firewall how to reassemble a data stream that has been divided into packets.

Back 8

identification

Front 9

The most effective security approach for a stateless packet filter is to deny all except _____ hosts.

Back 9

specified

Front 10

Criteria that _____ filters can be configured to use include IP header information, TCP or UDP port numbers, and ICMP message type.

Back 10

stateless

Front 11

A stateless filter compares a packet's header data against its _____ base and forwards only those packets that match a rule.

Back 11

rule

Front 12

____ ___ ___ includes specifications for six control flags in a TCP header.

Back 12

ITEF RFC 793

Front 13

Telnet uses port __.

Back 13

23

Front 14

The protocol number for TCP is _.

Back 14

6

Front 15

The protocol number for IGMP is _.

Back 15

2

Front 16

TCP port __ is used to filter out Web traffic.

Back 16

80

Front 17

A router receiving too much traffic is a possible cause for an ICMP source _____ message.

Back 17

quench

Front 18

Too many hops to destination is a possible cause of an ICMP time _____ message.

Back 18

exceeded

Front 19

The single bit of information in a TCP packet that indicates whether a packet is requesting a connection or whether a connection has already been established is the ___.

Back 19

ACK

Front 20

_____ packet filtering works by controlling the type of transport and the port number being used.

Back 20

Stateful

Front 21

Some traffic, such as ICMP uses packets that are hard to _____ reliably.

Back 21

filter

Front 22

Some stateful firewalls are able to examine the contents of packets as well as the headers for signs that they are _____.

Back 22

legitimate

Front 23

ICMP packets can be easily forged and used to _____ other communication.

Back 23

redirect

Front 24

____ is the most common command to use ICMP.

Back 24

PING

Front 25

The ICMP packet filter rule “____ _____” gives your computers the ability to ping external computers.

Back 25

echo request

Front 26

The ICMP packet filter rule “___ _____” prevents hackers from receiving replies to ping requests.

Back 26

echo reply

Front 27

The ICMP packet filter rule “____ _____” drops all other ICMP packets after setting your rules.

Back 27

ICMP block

Front 28

Secure HTTP uses port ___.

Back 28

443

Front 29

DNS uses port __ for connection attempts.

Back 29

53

Front 30

FTP uses port __ for the control port.

Back 30

21

Front 31

_____ is the act of identifying users and providing network services to them based on their identity.

Back 31

Authenticating

Front 32

Forms of authentication include _____, _____, and _____-_____.

Back 32

basic,centralized, and challenge-response

Front 33

A physical object such as a smart card is an example of a _____.

Back 33

token

Front 34

In the firewall _____ process, the firewall intercepts the request and prompts the user for a name and password.

Back 34

authentication

Front 35

After the user authentication step (in the firewall authentication process), the request is checked against the firewall's ____ base.

Back 35

rule

Front 36

In the firewall authentication process, after the user submits the proper information to the firewall, the user is _____.

Back 36

authenticated

Front 37

_____ _____ Firewall-1 provides the following authentications: user, session and client.

Back 37

Check Point

Front 38

User authentication is useful for employees in _____ offices.

Back 38

branch

Front 39

_____ authentication will help you establish limits to user access.

Back 39

Client

Front 40

A standard _____-__ is one in which the client, after being successfully authenticated, is allowed to access whatever resources the user needs.

Back 40

sign-on

Front 41

A specific sign-on system is one in which the client is required to _____ each time the user wants to access a server.

Back 41

authenticate

Front 42

_____ authentication calls for authentication to be made whenever a client wants to connect to a network resource and establish a session.

Back 42

Session

Front 43

Client and session authentication should only be used when a single user is coming from a single __ address.

Back 43

IP

Front 44

You should use both _____ and _____ authentication when the protocol in use is not HTTP, FTP, HTTPS, rlogin, or Telnet.

Back 44

client and session

Front 45

You should use _____ authentication when the protocol in use is HTTP, FTP, HTTPS, rlogin, or Telnet.

Back 45

user

Front 46

You should use _____ authentication when you want to scan the content of IP packets.

Back 46

user

Front 47

In _____ authentication an ACS alleviates the need to provide each server on the network with a separate database of usernames and passwords.

Back 47

centralized

Front 48

In centralized authentication ___ levels of trust are involved.

Back 48

two

Front 49

_____ authentication methods include TACACS+, RADIUS, and Kerberos.

Back 49

Centralized

Front 50

_____ was developed at MIT.

Back 50

Kerberos

Front 51

In the _____ system, after the client requests a file or other resource, the client is prompted for a username and password.

Back 51

Kerberos

Front 52

In the ______ system, after the AS grants the TGT, the TGS grants the session ticket.

Back 52

Kerberos

Front 53

In the _____ system, after the TGS grants the session ticket, the client gains access.

Back 53

Kerberos

Front 54

The Kerberos authentication server is also known as the ___.

Back 54

KDC

Front 55

The typical time length of a Kerberos ticket is _____ hours.

Back 55

eight

Front 56

_____ developed TACACS+.

Back 56

Cisco

Front 57

The MD5 algorithm produces a 128-bit code called a _____ digest.

Back 57

message

Front 58

_____ transmits authentication packets unencrypted across the network.

Back 58

RADIUS

Front 59

RADIUS uses UDP port ____ for accounting.

Back 59

1813

Front 60

Hashed passwords are passwords that have been _____.

Back 60

encrypted

Front 61

Challenge-response and password lists are examples of ___-____ passwords.

Back 61

one-time

Front 62

In ___-____ authentication, a physical object is required for a user to authenticate.

Back 62

two-factor

Front 63

In step 2 in the figure above, the _____ server authorizes the client.

Back 63

authentication

Front 64

In step 3 in the figure above, the request is checked against the firewall's _____ base.

Back 64

rule

Front 65

In the predefined IPSec policy - _____ (Respond Only) – level, the computer itself will not initiate communications using IPSec but can participate when another computer requires it.

Back 65

Client

Front 66

The predefined IPSec policy - _____ (Request Security) – level is being used when a host requests that IPSec be used to communicate but if the other computer is not configured for IPSec the two computers can still communicate.

Back 66

Server

Front 67

In the predefined IPSec policy - _____ _____ (Require Security) - a host with IPSec enabled only will communicate with other IPSec enabled hosts.

Back 67

Secure Server

Front 68

IPSec used between a private and a public network via a firewall, requires port Protocol ID __ to be opened if AH is used.

Back 68

51

Front 69

IPSec used between a private and a public network via a firewall, requires port IP protocol ID __ and UDP port ___ to be opened if ESP is used.

Back 69

50 / 500

Front 70

Digital _____ are used to authenticate individual users.

Back 70

certificates

Front 71

When using IPSec, the source gateway address, destination gateway address, and the packet size are _____.

Back 71

unencrypted

Front 72

_____ encrypts the IP connection between two machines.

Back 72

IPSec

Front 73

IPSec _____ machines.

Back 73

authenticates

Front 74

PGP and SSL are _____ applications.

Back 74

encryption

Front 75

In a 1997 survey by the CIO institute, ____ out of five civilian agency security managers did not know how often they were being attacked or by whom.

Back 75

four

Front 76

Packet sniffing is a _____ attack that scans for open ports.

Back 76

passive

Front 77

A man in the middle attack takes place when a hacker _____ part of an encrypted data session to gain control over the data being exchanged.

Back 77

intercepts

Front 78

The following encrypted _____ are available for use on the Internet: digital signatures, public keys, and private keys.

Back 78

codes

Front 79

Many organizations make use of ____, which holds publicly available information about digital certificates as well as individual users in the organization and the organization's network.

Back 79

LDAP

Front 80

A ___ is the framework that enables the distribution of digital certificates and public and private keys.

Back 80

PKI

Front 81

Digital certificates can be ____ client based and server based.

Back 81

both

Front 82

A server that is located in the network where people can apply to obtain a digital certificate that they can distribute is called a _____ _____.

Back 82

registration authority

Front 83

When you install Check Point _____-_ you are prompted to enter one hundred random characters of text.

Back 83

Firewall-1

Front 84

The use of a KDC is a form of ___ management.

Back 84

key

Front 85

A session ___ exists only during the length of communication between the hosts.

Back 85

key

Front 86

Check Point Firewall-1 uses a proprietary encryption scheme called ___.

Back 86

FWZ

Front 87

When using a _____ key system in an organization of 100 users who all need to exchange information, each user would be required to use one hundred separate keys.

Back 87

symmetric

Front 88

Asymmetric encryption is _____ than symmetric encryption.

Back 88

slower

Front 89

The name of the standard set of specifications for assembling and formatting digital certificates and encrypting data within them is _.___.

Back 89

X.509

Front 90

When you wipe a file with ___, all traces of it are deleted permanently.

Back 90

PGP

Front 91

If you use PGP or X.509, one aspect of the digital certificate that remains the same is the _____.

Back 91

subject

Front 92

___ makes use of symmetric and asymmetric keys.

Back 92

SSL

Front 93

E-mail, web traffic, and FTP file transfers can be protected by _____.

Back 93

IPSec

Front 94

In the figure above, encryption takes place at _ to protect the packet.

Back 94

A

Front 95

A ___exchange system is displayed in the figure above.

Back 95

key

Front 96

Other names for _____ servers are proxy service, application proxy, and application-level gateway.

Back 96

proxy

Front 97

A proxy server has ___ interfaces.

Back 97

two

Front 98

In a proxy server configuration, the firewall should be directly connected to the _____.

Back 98

Internet

Front 99

_____ servers can conceal internal clients, block URLs, and block and filter content.

Back 99

Proxy

Front 100

A proxy server protected network appears to be a _____ machine to an external client.

Back 100

single

Front 101

Full text URLs are typically _____ by a proxy server.

Back 101

blocked

Front 102

Your _____ server should filter or block Java applets, executable e-mail attachments, and activeX controls.

Back 102

proxy

Front 103

Time, IP addresses, and port numbers can be _____ out by a proxy server.

Back 103

filtered

Front 104

When a firewall log is used to determine whether an unauthorized user has accessed resources that should be protected, its function is to _____ intrusions.

Back 104

detect

Front 105

When a firewall log can point to ports, machines, or other vulnerable computers through which hackers can gain entry, its function is to uncover _____.

Back 105

weaknesses

Front 106

Some proxy servers use _____ to notify you if a possible attack is in progress.

Back 106

alerts

Front 107

One consideration that must be taken into account when choosing a proxy server (as a network grows) is _____.

Back 107

scalability

Front 108

In _____ _____ no proxy server needs to be specified for FTP and Gopher connections because the browser can use the SOCKS standard.

Back 108

Internet Explorer

Front 109

HTTP, DNS, and SMTP traffic can be _____ by a proxy server.

Back 109

monitored

Front 110

___ sharing is a feature of Windows 2000 Advanced Server that allows you to create multiple proxies that are in use simultaneously.

Back 110

Web

Front 111

_____ overflows are the most common problem a proxy server can fall victim to.

Back 111

Buffer

Front 112

A _____ firewall combines several different security technologies.

Back 112

hybrid

Front 113

A _____ proxy can be configured to be totally invisible to an end user.

Back 113

transparent

Front 114

An _____ proxy requires the client software to be configured to use the proxy server.

Back 114

explicit

Front 115

_____ is typically used to forward all target traffic to the proxy at a single target port.

Back 115

SOCKS

Front 116

A _____ consists of an IP address and a port number.

Back 116

socket

Front 117

Port TCP/____ is the typical target port that SOCKS uses to direct all traffic from the client to the proxy.

Back 117

1080

Front 118

_____ is the name of the free SOCKS application available from Permeo Technologies.

Back 118

SocksCap

Front 119

T.REX, WinGate, and Squid are open source _____ applications.

Back 119

proxy

Front 120

_____ is the most popular proxy server for home and small business environments.

Back 120

WinGate

Front 121

Symantec Enterprise Firewall filters content using a technology it calls _____.

Back 121

WebNOT

Front 122

The Windows ____ Server operating system is required to support ISA Server.

Back 122

2000

Front 123

In step 3 of the figure above, the proxy server recreates the packet with a different _____ address.

Back 123

source

Front 124

In step 5 of the figure above, the returned packet is inspected and compared against the ____ base.

Back 124

rule

Front 125

In step 1 of the figure above, an internal host makes a _____ to access a Web site.

Back 125

request