Question 1

A(n) ____________________ is hardware or software that blocks or allows transmission of information packets based on criteria such as port, IP address, and protocol.

Accepted Answer

The answer of A(n) ____________________ is hardware or software that...

Question 2

Match each item with a statement below.
-16-bit value aids in the division of the data stream into packets of information.

Accepted Answer

The identification header field is a 16-bit value used in the IP header to help in the fragmentation and reassembly of packets, ensuring that data streams are properly divided and reassembled.

Question 3

Filtering by TCP or UDP port number is commonly called port filtering or ____________________ filtering.

Accepted Answer

The answer of Filtering by TCP or UDP port number...

Question 4

Match each item with a statement below.
-Originally developed as a means of enabling large packets to pass through early routers that had frame size limitations.

Accepted Answer

Fragmentation was originally developed as a means of enabling large packets to pass through early routers that had frame size limitations.

Answer: B
 The identification header field is a 16-bit value that aids in the division of the data stream into packets of information.

Answer: C
 A router is a networking device that forwards data packets between computer networks.

Answer: D
 ICMP (Internet Control Message Protocol) is a protocol used by network devices, including routers, to send error messages and operational information about network conditions.

Answer: E
 The protocol header field identifies the protocol used at the Transport layer of the OSI model.

Answer: F
 Firewall appliances are hardware devices that enforce security policies for a network, by filtering incoming and outgoing network traffic.

Answer: G
 Stateful packet filtering is a firewall technology that tracks the state, or context, of active network connections and only allows traffic that belongs to an established connection.

Answer: A
 A packet is a unit of data that is transmitted over a packet-switched network.

Answer: I
 Stateless packet filtering is a firewall technology that filters packets based on their source and destination addresses, without considering the context of the connection.

Question 5

When Web services are offered outside the firewall, ____________________ traffic is prevented from reaching the internal networks via the implementation of some form of proxy access or DMZ architecture.

Accepted Answer

The answer of When Web services are offered outside the...

Question 6

The ____ flag tells a host to immediately terminate a connection.

Accepted Answer

The RST (reset) flag is used to immediately terminate a TCP connection. This flag is commonly used when a connection is no longer valid or has been compromised.

Question 7

Match each item with a statement below.
-Reviews packet header content and makes decisions on whether to allow or drop the packets based on whether a connection has actually been established between an external host and an internal one.

Accepted Answer

The answer of Match each item with a statement below.
-Reviews...

Question 8

Match each item with a statement below.
-Identifies the IP protocol that was used in the data portion of the packet and should receive the data at its destination

Accepted Answer

The protocol header field identifies the IP protocol that was used in the data portion of the packet and should receive the data at its destination.

Answer: A
 A packet is the basic unit of information that is exchanged between devices on the Internet. It contains a header and a payload.

Answer: C 
 A router is a networking device that forwards data packets between computer networks.

Answer: D 
 ICMP (Internet Control Message Protocol) is a protocol used by network devices to send error messages indicating, for example, that a requested service is not available or that a host or network is unreachable.

Answer: H 
 Fragmentation is the process of dividing a packet into smaller packets that can be transmitted over a network with a smaller maximum transmission unit (MTU).

Answer: F 
 Firewall appliances are network security devices that monitor and filter incoming and outgoing network traffic based on predefined security rules.

Answer: G 
 Stateful packet filtering is a security mechanism that tracks the state of active network connections and allows only authorized traffic to pass through the firewall.

Answer: I 
 Stateless packet filtering is a security mechanism that examines each packet individually and filters based only on information contained in the packet header, without tracking the state of active network connections.

Question 9

A stateless or stateful packet filter that supports active ____ must allow all traffic coming from TCP Port 20 as well as outbound traffic coming from ports above 1023.

Accepted Answer

The active keyword refers to FTP's active mode, which uses TCP Port 20 for data transfer. Therefore, a stateless or stateful packet filter that supports active FTP must allow all traffic coming from TCP Port 20. Additionally, outbound traffic coming from ports above 1023 must also be allowed to establish the control connection for FTP. ICMP and UDP are not relevant for FTP's active mode, so they can be eliminated as options.

Question 10

Match each item with a statement below.
-The most common packet filter.

Accepted Answer

The answer of Match each item with a statement below.
-The...

Question 11

It is good practice to block ____ access to all internal servers from the public networks.

Accepted Answer

Telnet is an older protocol used for accessing remote computers but it transmits data, including passwords, in plain text, making it highly insecure for use over public networks. Blocking Telnet access helps protect internal servers from unauthorized access and potential security breaches.

Question 12

The ____ is a structure for organizing Internet names associated with IP addresses.

Accepted Answer

The Domain Name System (DNS) is specifically designed to organize and translate domain names into their corresponding IP addresses, making it easier to locate resources on the Internet. TCP, HTTP, and SMTP are all protocols used for other functions on the Internet.

Question 13

Packets requesting a connection have the ACK bit set to 0; those that are part of an ongoing connection have the ACK bit set to ____.

Accepted Answer

Packets that are part of an ongoing connection have the ACK bit set to 1. A value of 0 indicates that it is a packet requesting a connection (SYN). Values other than 0 or 1 are not used for the ACK bit. Option A (-1) and Option D (99) are not valid values for the ACK bit.

Question 14

A stateful filter has a ____, which is a list of current connections.

Accepted Answer

A stateful filter keeps track of the state of connections by maintaining a state table, which is a list of current connections. This allows the filter to differentiate between legitimate and illegitimate packets and can help it enforce a security policy more effectively. The other choices are not accurate descriptors of the functionality of a stateful filter.

Question 15

The proper rule ____________________ ensures that the most resource-intensive actions are performed after the most restrictive ones, thereby reducing the number of packets that undergo intense scrutiny.

Accepted Answer

The answer of The proper rule ____________________ ensures that the...

Question 16

Match each item with a statement below.
-Packets that can be easily forged and used to redirect other communications.

Accepted Answer

ICMP (Internet Control Message Protocol) packets can be easily forged and are often used in attacks to redirect or disrupt communications. This is because ICMP is used for sending error messages and operational information indicating, for example, that a service is not available or a router cannot be reached, making it a target for misuse in redirecting traffic.

Question 17

Match each item with a statement below.
-Consists of two parts: the header and the data.

Accepted Answer

A packet consists of two parts: the header and the data.

Answer: B
 The identification header field is a field in the IP header that identifies the packet and can be used for reassembly if the packet is fragmented.

Answer: C
 A router is a networking device that forwards data packets between computer networks.

Answer: D
 ICMP (Internet Control Message Protocol) is a protocol used for sending error messages and operational information about network conditions.

Answer: E
 The protocol header field is a field in the packet header that identifies the protocol being used to transmit the data.

Answer: F
 Firewall appliances are hardware devices that are used to protect computer networks from unauthorized access and other security threats.

Answer: G
 Stateful packet filtering is a type of firewall that keeps track of the state of network connections and can block packets based on that state.

Answer: H
 Fragmentation is the process of breaking up a large packet into smaller packets so that it can be transmitted across a network.

Answer: I
 Stateless packet filtering is a type of firewall that examines individual packets without considering the context of the connection.

Question 18

Match each item with a statement below.
-Standalone hardware and software devices that have self-contained components.

Accepted Answer

Firewall appliances are standalone hardware and software devices that have self-contained components.

Answer: C
 Routers are networking devices that forward data packets between computer networks.

Answer: G
 Stateful packet filtering is a type of firewall technology that monitors state information of active connections to filter traffic.

Answer: H
 Fragmentation is the process of breaking larger packets into smaller packets to allow for transmission over networks with smaller maximum transmission unit (MTU) sizes.

Answer: I
 Stateless packet filtering is a type of firewall technology that filters traffic based on predetermined rules, without monitoring state information of active connections.

Answer: A
 A packet is a unit of data that is transmitted between computers over a network.

Answer: D
 ICMP (Internet Control Message Protocol) is a protocol used for sending error messages and operational information about the status of a network.

Answer: E
 Protocol header fields are parts of network protocol data units (PDUs) that contain information specific to a particular protocol.

Answer: B
 Identification header fields are parts of network protocol data units (PDUs) that identify the purpose or type of the PDU.

Question 19

Match each item with a statement below.
-Maintains a record of the state of a connection when filtering packets.

Accepted Answer

Stateful packet filtering maintains a record of the state of a connection, allowing only packets that fit an established pattern to pass through.

Answer: B
 Identification header field is a field in the IP packet header that is used to uniquely identify the packet.

Answer: C
 A router forwards packets between networks based on their destination addresses.

Answer: D
 Internet Control Message Protocol (ICMP) is a protocol used by network devices to communicate errors and status information.

Answer: E
 Protocol header field is a field in the IP packet header that identifies the protocol being used.

Answer: F
 Firewall appliances are hardware devices designed to protect computer networks from unauthorized access.

Answer: A
 A packet is a unit of data that is transmitted over a network.

Answer: H
 Fragmentation is the process of dividing a packet into smaller packets to accommodate network limitations.

Answer: I
 Stateless packet filtering examines packets in isolation and does not maintain any state information about connections.

Question 20

A single bit of information in a TCP packet -the ____________________ flag -indicates if a packet is requesting a connection or a connection has already been established.

Accepted Answer

The answer of A single bit of information in a...

Quiz 5: Packet Filtering

A(n) ____________________ is hardware or software that blocks or allows transmission of information packets based on criteria such as port, IP address, and protocol.

Match each item with a statement below. -16-bit value aids in the division of the data stream into packets of information.

Filtering by TCP or UDP port number is commonly called port filtering or ____________________ filtering.

Match each item with a statement below. -Originally developed as a means of enabling large packets to pass through early routers that had frame size limitations.

When Web services are offered outside the firewall, ____________________ traffic is prevented from reaching the internal networks via the implementation of some form of proxy access or DMZ architecture.

The ____ flag tells a host to immediately terminate a connection.

Match each item with a statement below. -Reviews packet header content and makes decisions on whether to allow or drop the packets based on whether a connection has actually been established between an external host and an internal one.

Match each item with a statement below. -Identifies the IP protocol that was used in the data portion of the packet and should receive the data at its destination

A stateless or stateful packet filter that supports active ____ must allow all traffic coming from TCP Port 20 as well as outbound traffic coming from ports above 1023.

Match each item with a statement below. -The most common packet filter.

It is good practice to block ____ access to all internal servers from the public networks.

The ____ is a structure for organizing Internet names associated with IP addresses.

Packets requesting a connection have the ACK bit set to 0; those that are part of an ongoing connection have the ACK bit set to ____.

A stateful filter has a ____, which is a list of current connections.

The proper rule ____________________ ensures that the most resource-intensive actions are performed after the most restrictive ones, thereby reducing the number of packets that undergo intense scrutiny.

Match each item with a statement below. -Packets that can be easily forged and used to redirect other communications.

Match each item with a statement below. -Consists of two parts: the header and the data.

Match each item with a statement below. -Standalone hardware and software devices that have self-contained components.

Match each item with a statement below. -Maintains a record of the state of a connection when filtering packets.

A single bit of information in a TCP packet -the ____________________ flag -indicates if a packet is requesting a connection or a connection has already been established.