Where does the CRC originate in a network frame group of answer choices?

A network packet is a small amount of data sent over Transmission Control Protocol/Internet Protocol (TCP/IP) networks. The packet size is around 1.5 kilobytes for Ethernet and 64 KB for IP payloads.

A packet is the unit of data routed between an origin and a destination on the internet or other packet-switched network -- or networks that ship data around in small packets.

What is a packet-switched network?

Everything on the internet, including emails and webpages, makes use of network packets to send information between users and recipients. This approach to sending a network packet ensures information reliability so that data does not have to be sent as a single large file.

Each packet sent includes information such as the source and destination, protocols or identification.

How does a network packet work?

When any file, like an email message, Hypertext Markup Language, Graphics Interchange Format or Uniform Resource Locator request is sent on the internet, it is broken down into small chunks, or bytes. The TCP layer of TCP/IP divides the file into bytes for efficient routing. Typically, a packet holds 1,000 to 1,500 bytes of information.

Each packet is separately numbered and includes the internet address of the destination. The individual packets for a given file may take different routes over the internet. Upon arrival at their destination, the packets are reassembled into the original file by the TCP layer at the receiving end.

Depending on the type of network, packets can also be referred to by names such as block, cell, frame or segment.

A packet-switching scheme is an efficient way to handle transmissions on a connectionless network, such as the web. An alternative scheme, circuit-switched transmission, is used for voice networks. In circuit switching, lines in the network are shared among many users as with packet switching. However, each connection requires the dedication of a particular path for the duration of the connection.

What are the parts of a network packet?

Network packets are made up of three different parts: header, payload and trailer. Conceptually, they're like a postal package. In this scenario, the header is the box/envelope, the payload is content and the trailer is the signature.

The header contains instructions related to the data in the packet. These instructions can include the following:

• checksum, which detects errors;
• 16-bit identification number;
• flags to let a router know if it can fragment a packet;
• fragmentation offsets, which reconstruct fragmented packets;
• destination address;
• number of hops a packet can make;
• IP;
• length of the packet -- but not always, as some networks have fixed-length packets;
• size of the header and payload;
• time-to-live;
• originating address;
• packet number, in relation to the packet sequence;
• protocol or what type of packet is transmitted; and
• synchronization or the few bits that enable the packet to match up to the network.

The payload is the data within the packet. This is the basic information that the packet delivers to the destination. The payload is often padded with blank information to accommodate a fixed-length packet.

Sometimes called the footer, trailers are bits that signify the end of a packet. These bits inform the receiving device that it has reached the end of the packet. Trailers may also include a type of error checking protocol.

The most common type of error checking is called a cyclic redundancy check (CRC). On certain computer networks, CRC adds up all of the 1s in the payload before storing the result as a hexadecimal value. Upon receipt, the receiving device compares the sum of 1s in the payload to the value stored in the trailer. If the values match, it's a good packet. If they do not match, the receiving device sends a request to the originating device to resend the packet.

Common questions and answers about network packets

What is network packet loss?

Packet loss occurs when a packet with data fails to arrive at its destination. Internet packet loss can happen for several reasons, including mistakes made during data transmission and network congestion.

What is a network packet broker?

Network packet broker technologies implement various monitoring tools to access and analyze network packets or traffic traveling across a network. A network packet broker functions like a manager of network traffic.

What is network packet sniffing (traffic analysis)?

Network traffic analysis is often referred to as packet sniffing. A packet analyzer or network sniffer can be a piece of hardware or software that monitors network traffic. Network packet sniffers examine streams of data packets flowing between computers on a network. They also analyze traffic between networked computers and the internet.

Examples of packet sniffing tools are NetFlow Analyzer, Tcpdump and Wireshark.

What is network packet capture?

Packet capture is the interception of data packets that cross through a specific point in the network. Captured in real time, the packet is stored for analysis, archived, downloaded or discarded.

What is the network packet size in a SQL server?

The default network packet size in an Structured Query Language (SQL) server is 4,096 bytes. The largest network packet size for encrypted transmissions is 16,383 bytes.

How to troubleshoot packet loss on a network?

Troubleshooting network packet loss is done using application performance monitoring tools.

Here are five steps used to troubleshoot:

1. Isolate the root cause of packet loss.
2. Assess the service provider based on the results of step 1.
3. Configure network settings.
4. Check all network hardware components.
5. Monitor for potential packet loss.

What is the requirement of a connectionless packet-switched network?

The only requirement for connectionless packet-switched networks is an identifier. The network will determine the route each packet takes over a virtual circuit built for the duration of the packet delivery.

What is a network packet generator?

A network packet generator is a tool that enables the administrator to construct Address Resolution Protocol/Reverse ARP, Cisco Discovery Protocol, Internet Control Message Protocol, and User Datagram Protocol (UDP) or raw packets and send them either as a single packet or multiple packets. This packet of information can be sent to an IPv4 address or IPv6 address.

What is the difference between a packet and a datagram?

The words packet and datagram are similar in meaning. A protocol similar to TCP, UDP uses the term datagram instead of packet.

Two systems on the same network may have NICs with the same MAC address

In a wired network, a charge on a wire represents a zero while no charge represents a one

A NIC reads the data portion of a frame to determine the address of the receiving system

The FCS uses a type of binary math called a cyclic redundancy check (CRC) that the receiving NIC uses to verify that the data arrived intact.

When a frame arrives at the switch, the switch makes an exact copy of the frame and sends it to every other system on the network

When a NIC sends a frame that contains the broadcast address, every NIC on the network processes that frame

No two systems on the same network can share the same IP address

Routers use logical addresses to forward data

The TCP/IP model consists of six layers

Cabling, physical addresses, NICs, and switches are included in the Link layer of the TCP/IP model

The Network Interface layer of the TCP/IP model maps to the Network layer of the OSI model

The Transport layer of the TCP/IP model uses both connection-oriented and connectionless protocols

TCP is a connection-oriented protocol.

The Link layer of the TCP/IP model combines features of the top three layers of the OSI model

How many layers does the OSI model contain

Which layer of the OSI model defines a method of moving radio waves

How long is a MAC address

12 hexadecimal characters

Which two parts are included in a MAC address

1. The Organizationally Unique Identifier and the device ID of the NIC

A MAC address is also known as a(n) __________ address

An oscilloscope is a powerful tool that enables a technician to see __________.

All NICs on the same network must use the same __________, or they will not be able to communicate with other NICs

Where does the CRC originate in a network frame

the sending NIC attaches it

Which layer of the OSI model adds source and destination MAC addresses to frames

Frames in most wired networks hold at most __________.

How are incoming frames handled by a switch

The frames are sent only to the interface associated with the destination MAC address (if the MAC is recorded in its memory).

How does the receiving station on a network use the CRC to verify that it received accurate data

It uses the same divisor as the sending station to find the same remainder.

Which of the following is a broadcast MAC address

Which statement best describes Logical Link Control (LLC)

It is a sublayer of the Data Link Layer

Which layer of the OSI model is the only layer divided into two sublayers

Which layer of the OSI model assembles the data it receives into pieces called packets

What device splits a large network into subnets

What unique numeric identifier is assigned to each device on the network by the IP protocol in the OSI model's Network layer

Routers function at which layer of the OSI model

Which layer of the OSI model uses routers and IP addresses to ensure that packets arrive at the correct system

Which OSI model layer initializes requests for packets that were not received in good order

Which layer of the OSI model manages the opening and closing of the connection between applications

Which statement best describes an Application Programming Interface

It provides programmers with a standard way to extend an application's capabilities.

Routers function at which layer of the TCP/IP model

Which layer of the TCP/IP model is mapped to the bottom two layers of the OSI model

Which layer of the TCP/IP model performs IP addressing functions?

Which layer of the TCP/IP model uses a connection-oriented protocol?

Which layer of the TCP/IP model is mapped to the top three layers of the OSI model?

For a network technician, one benefit of understanding the OSI seven-layer model and how traffic in an actual network works through the model is applying this knowledge to __________.

The organization responsible for developing the OSI model of networking is the ____________________.

UTP cabling usually contains __________ pairs of wires that can transmit and receive data

The unique identifier burned into a ROM chip in the NIC is known as the ____________________ address

A MAC address is usually written in ____________________ notation

If you have a Windows system, type ____________________ from the command prompt to display the MAC address for your computer.

The current term for the MAC address numbering name space, as defined by the IEEE, is ____________________.

A(n) ____________________ is a tool that enables a technician to see electrical pulses.

A container created at the OSI Data Link layer for carrying discrete chunks of data across a network is called a(n) ____________________.

Computer data is ____________________, which means it is made up of streams of ones and zeroes.

By using the ____________________ MAC address, a NIC can send a frame that every other NIC on the network will process

A sublayer of the OSI seven-layer model, the ____________________ describes the function of a NIC that talks to the network operating system, handles multiple network protocols and provides flow control

Switches handle traffic using ____________________ addresses, so they operate at Layer 2

Any device that deals with a MAC address is part of the OSI model's ____________________ layer

Although one may argue that the NIC operates at more than one layer of the OSI model, the generally accepted answer is that this device belongs at the ____________________ layer because it assigns the MAC address

Named after two protocols, ____________________ is really a protocol suite designed to work together.

The decimal value for each 8-bit portion of an IP address can range from ____________________ to ____________________.

In a TCP/IP network, each system has two unique identifiers: the ____________________ address (physical address) and the ____________________ address (logical address). (Both should be represented in capital letters.)

When handed to the NIC, each IP packet is enclosed in a ____________________ arranged at the LLC sublayer

In a TCP/IP network, an IP ____________________ includes the destination IP address, the source IP address, and the data

The OSI model's ____________________ layer uses sequencing numbers determine the total number of segments and how to put them back together

If you want to see how many sessions are running on a TCP/IP network, you should use the ____________________ program from the command prompt

The OSI model's Session layer initiates sessions, accepts incoming sessions, and ______________ and _____________ existing sessions

The OSI model's Presentation layer translates data from lower layers into a format usable by the ____________________ layer, and vice versa

Layer 6 of the OSI model is called the ____________________ layer

All operating systems have ____________________ that programmers can use to make their programs network aware

The TCP/IP model is a(n) ____________________ (number) layer model

A(n) ____________________ is a number between 1-65,536 and it is a logical value assigned to specific applications or services

The ____________________ layer of the TCP/IP model uses segments and datagrams as its Protocol Data Units

Layer 6 of the OSI model is included in the ____________________ layer of the TCP/IP model.

What is 255.255.255.0 in binary

11111111.11111111.11111111.00000000

What is the binary number 10101010 in decimal