EUNICE
NSA Computer Network Test WITRH QUESTIONS AND 100%
SURE ANSWERS
What are the 2 keys to 1. Binary is the intermediary
decimal/hex/octal/binary conversions? 2. BE CAREFUL
What is endianness? The order or sequence of bytes of a word of digital data in computer memory
The most significant byte is stored at the smallest memory address and the least
What is big endian?
significant byte is stored at the largest memory address
The most significant byte is stored at the largest memory address and the least
What is little endian?
significant byte is stored at the smallest memory address
With regards to endianness, what is Network order refers to data being sent across a medium in big endian (most
"network order?" significant byte first) in the Internet Protocol
What is the endianness of most processor Little endian
architectures, including Intel x86, AMD x86-
64, ARM, and RISK-V?
1. When sending data between two different computers. The communication
protocol must ensure that even if the two computers' endianness differs, the data
isn't corrupted. IP does this by defaulting to network order.
In what two situations is paying attention to
endianness important?
2. When investigating memory dumps. You must understand the endianness of the
computer whom the memory dump comes from to properly be able to analyze the
dump.
1. Registers
2. Caches
4 part memory hierarchy
3. Main memory
4. Storage
How many bytes are in a word? 2 bytes
How many bytes are in a single ASCII 1 byte
character?
How many bytes are in a single UTF-8 1 to 4 bytes (variable)
character?
From low to high addresses:
1. Text segment (code / executable instructions)
What are the 5 segments of a process's 2. Initialized data segment
memory? 3. Uninitialized data segment
4. Heap segment (dynamic memory allocations, grows toward high addresses)
5. Stack segment (function arguments, local variables, grows toward low addresses)
An SSD is a form of memory that uses integrated circuits for persistent memory (flash
What is a solid state drive?
memory)
1/8
, An HDD is a form of memory that uses magnetic properties to store and retrieve
What is a hard disk drive?
digital data on spinning disks
The section of memory in which normal user processes run. Processes running in this
space only have access to a limited part of this space (the process's own space and
What is user space?
any shared memory sections). Process in this space can only access kernel space
through controlled system calls.
The section of memory in which kernel processes run. Processes running in this
What is kernel space? space have access to all memory spaces, user and kernel. Significantly higher
privilege than user space.
1: Physical
2: Data Link
3: Network
Name the seven layers of the OSI model 4: Transport
5: Session
6: Presentation
7: Application
1: Link
2: Internet
Name the four layers of the TCP/IP model
3: Transport
4: Application
As data travels down the TCP/IP stack, the packet of the higher layer becomes the
payload of the packet of the next lower layer.
What is encapsulation?
As data travels up the TCP/IP stack, the payload of each packet is extracted at each
layer of the stack.
What is the primary concern of the The transmission of raw bits
Physical layer of the OSI model?
1. Grouping raw bits from the Physical layer in to frames
What are the primary 3 concerns of the
2. Detect and possibly correct errors from the Physical layer (checksum)
Data Link layer of the OSI model?
3. The transmission of data frames between nodes on a network
1. Provide an addressing scheme
What are the 3 primary concerns of the
2. The forwarding/routing of data packets between networks
Network layer of the OSI model?
3. Frame fragmentation with MTU field
Provide host-to-host communication services for applications (such as connection-
What is the primary concern of the
oriented communication, connectionless communication, reliability, flow control, and
Transport layer of the OSI model?
multiplexing) through the transmission of data segments
Provides a mechanism for:
(1) Delimiting data flow
What are the four primary concerns of the
(2) Synchronizing data flow
Session layer of the OSI model?
(3) Maintaining state
(4) Checkpoint/recovery scheme
How data is formatted in a given session, including:
(1) Compression
What are the four primary concerns of the
(2) Encryption
Presentation layer of the OSI model?
(3) Byte-ordering
(4) Encoding
What is the primary concern of the Provide services that allow end users to easily interface across the network
Application layer of the OSI model?
At what level of the OSI model does a web The Application layer
application firewall operate?
2/8
NSA Computer Network Test WITRH QUESTIONS AND 100%
SURE ANSWERS
What are the 2 keys to 1. Binary is the intermediary
decimal/hex/octal/binary conversions? 2. BE CAREFUL
What is endianness? The order or sequence of bytes of a word of digital data in computer memory
The most significant byte is stored at the smallest memory address and the least
What is big endian?
significant byte is stored at the largest memory address
The most significant byte is stored at the largest memory address and the least
What is little endian?
significant byte is stored at the smallest memory address
With regards to endianness, what is Network order refers to data being sent across a medium in big endian (most
"network order?" significant byte first) in the Internet Protocol
What is the endianness of most processor Little endian
architectures, including Intel x86, AMD x86-
64, ARM, and RISK-V?
1. When sending data between two different computers. The communication
protocol must ensure that even if the two computers' endianness differs, the data
isn't corrupted. IP does this by defaulting to network order.
In what two situations is paying attention to
endianness important?
2. When investigating memory dumps. You must understand the endianness of the
computer whom the memory dump comes from to properly be able to analyze the
dump.
1. Registers
2. Caches
4 part memory hierarchy
3. Main memory
4. Storage
How many bytes are in a word? 2 bytes
How many bytes are in a single ASCII 1 byte
character?
How many bytes are in a single UTF-8 1 to 4 bytes (variable)
character?
From low to high addresses:
1. Text segment (code / executable instructions)
What are the 5 segments of a process's 2. Initialized data segment
memory? 3. Uninitialized data segment
4. Heap segment (dynamic memory allocations, grows toward high addresses)
5. Stack segment (function arguments, local variables, grows toward low addresses)
An SSD is a form of memory that uses integrated circuits for persistent memory (flash
What is a solid state drive?
memory)
1/8
, An HDD is a form of memory that uses magnetic properties to store and retrieve
What is a hard disk drive?
digital data on spinning disks
The section of memory in which normal user processes run. Processes running in this
space only have access to a limited part of this space (the process's own space and
What is user space?
any shared memory sections). Process in this space can only access kernel space
through controlled system calls.
The section of memory in which kernel processes run. Processes running in this
What is kernel space? space have access to all memory spaces, user and kernel. Significantly higher
privilege than user space.
1: Physical
2: Data Link
3: Network
Name the seven layers of the OSI model 4: Transport
5: Session
6: Presentation
7: Application
1: Link
2: Internet
Name the four layers of the TCP/IP model
3: Transport
4: Application
As data travels down the TCP/IP stack, the packet of the higher layer becomes the
payload of the packet of the next lower layer.
What is encapsulation?
As data travels up the TCP/IP stack, the payload of each packet is extracted at each
layer of the stack.
What is the primary concern of the The transmission of raw bits
Physical layer of the OSI model?
1. Grouping raw bits from the Physical layer in to frames
What are the primary 3 concerns of the
2. Detect and possibly correct errors from the Physical layer (checksum)
Data Link layer of the OSI model?
3. The transmission of data frames between nodes on a network
1. Provide an addressing scheme
What are the 3 primary concerns of the
2. The forwarding/routing of data packets between networks
Network layer of the OSI model?
3. Frame fragmentation with MTU field
Provide host-to-host communication services for applications (such as connection-
What is the primary concern of the
oriented communication, connectionless communication, reliability, flow control, and
Transport layer of the OSI model?
multiplexing) through the transmission of data segments
Provides a mechanism for:
(1) Delimiting data flow
What are the four primary concerns of the
(2) Synchronizing data flow
Session layer of the OSI model?
(3) Maintaining state
(4) Checkpoint/recovery scheme
How data is formatted in a given session, including:
(1) Compression
What are the four primary concerns of the
(2) Encryption
Presentation layer of the OSI model?
(3) Byte-ordering
(4) Encoding
What is the primary concern of the Provide services that allow end users to easily interface across the network
Application layer of the OSI model?
At what level of the OSI model does a web The Application layer
application firewall operate?
2/8
