IS 410 Practice Question --

Which term matches ALL of these facts?

It is the actual physical connection between the sender and the receiver.

It turns bits (1s and 0s) into signals: electrical signals in copper, light pulses in fiber, or radio waves for wireless.

The other 4 layers only prepare the message.

The ______ layer is the one that actually moves it.

It includes the hardware (computers, modems, switches) and the media (cables, satellites).

It sets the type of connection and the kind of signal used. Its data unit is bits.

The Physical layer (layer 1).

Which term matches ALL of these facts?

The ______ layer controls the physical layer by deciding WHEN to transmit.

It formats messages by marking where they start and end.

It detects errors from transmission and may fix them.

Its data unit is the frame.

It uses MAC addresses.

Ethernet works here.

NICs and switches work at this layer.

The Data Link layer (layer 2). - not physical layer which actually sends signals

Which term matches ALL of these facts?

The ______ layer performs routing: it picks the next computer to send the message to.

It finds the address of that computer if it doesn't already know it. It moves data from the source host to the destination host.

Its data unit is the packet.

Its main protocol is IP. It uses IP addresses.

Routers work up to this layer and no higher.

-- main job is routing

The Network layer (layer 3). not transport layer which sets up the connection

Which term matches ALL of these facts?

The ______ layer links the application software to the network.

It sets up end-to-end connections between sender and receiver when needed.

It breaks long messages into smaller pieces and puts them back together at the end.

It detects lost messages and asks for them to be resent.

It uses port numbers to find the right application.

Its data unit is the segment.

Its protocols are TCP and UDP.

— main job is setting up connection and segmenting

The Transport layer (layer 4). Not Network Layer which focuses on routing

Which term matches ALL of these facts?

The ______ layer is the user's access to the network.

The application software decides what messages get sent. HTTP, SMTP, IMAP, and POP work here.

Its address is the URL or domain name.

Its data unit is the message.

It is the top layer of the 5-layer model.

— main function is to create the message

The Application layer (layer 5).

Which term matches ALL of these facts?

Clients (laptops, phones, desktops) send requests.

A server stores data or runs services and sends responses.

They are connected through the Internet.

Page 3 of Lecture 2 shows this ______ network.

Client-server network

Which term matches ALL of these facts?

The ______ has 7 layers.

Its top 3 layers are Application, Presentation, and Session.

The Internet model squeezes those 3 into one Application layer.

The OSI model - Open Systems Interconnection

Which term matches ALL of these facts?

The ______ has 5 layers: Application, Transport, Network, Data Link, Physical.

At the sender, data goes DOWN the layers and each layer adds a header.

At the receiver, data goes UP and each layer removes its header.

Also called the TCP/IP model.

The Internet model (5-layer model).

Which term matches ALL of these facts?

The ______ is the name for the unit of data at each layer.

“what we call data at each layer”

Application : Messahe
Transport : Segment
Network : Packet
Data Link : Frame
Physical : Bits

Many , Students, Prefer, Fresh, Bread

PDU (Protocol Data Unit).

Which term matches ALL of these facts?

Its PDU name is used at the transport layer.

TCP breaks a long message into many of these.

UDP fits the whole message into just one of these.

Each one has a source port and destination port in its header.

The Maximum ______ Size (MSS) is set during the TCP handshake.

Segment. “Many Students Prefer Fresh Bread”

Which term matches ALL of these facts?

Its PDU name is used at the network layer.

Each TCP or UDP segment goes inside exactly one of these.

Its header holds the source IP and destination IP address.

It does NOT change while the message travels.

Only the sender and final receiver make or remove it.

Network Layer = Packet (IP packet). ( Message, Segment, Packet, Frame, Bits )

Which term matches ALL of these facts?

Its PDU name is used at the data link layer.

Ethernet uses this. It holds MAC addresses.

At each stop along the way, the old one is removed and a new one is created.

It only lives long enough to move the message one hop.

Data Link Layer = Frame (Ethernet frame).

Message, Segment, Packet, Frame, Bits

Which term matches ALL of these facts?

______ make sure hardware and software from different vendors can work together.

Customers are not locked into one vendor.

This promotes competition and holds down prices.

Examples: HTTP, TCP, IP, Ethernet.

Network standards.

Which term matches ALL of these facts?

______ is the software that controls the network.

It manages users, shared files, and devices like printers.

It is one of the 5 LAN components.

It was the answer to a sample exam question.

Network Operating System (NOS).

Which term matches ALL of these facts?

______ is the protocol for the Web.

A browser sends a request.

The web server sends back a response.

Request = request line, request header, request body.

Response = response status, response header, response body.

Uses TCP port 80. Application layer protocol.

HTTP (Hypertext Transfer Protocol).

Which term matches ALL of these facts?

______ sends email. It moves mail from the user's computer to the mail server, and from server to server.

Main function is to send and receive mail

NOT - not retrieve the main fully to the point where the user can read it.

Uses TCP port 25.

SMTP (Simple Mail Transfer Protocol)

Which term matches ALL of these facts?

______ gets email from the mail server down to the user's computer. ( gets mail from SMTP )

Main function is to - READ mail and fully retrieve the content

NEVER to send mail.

Application layer protocols.

IMAP - Internet Message Access Protocol
POP - Post Office Protocol

Which term matches ALL of these facts?

It is made of thin copper wires twisted together in pairs.

It is the common Ethernet cable used in LANs.

Twisted pair cable.

Which term matches ALL of these facts?

A copper wire in the center, with shielding around it.

It is the kind of wire used for cable TV.

A cable modem connects over this kind of line.

Coaxial cable.

Which term matches ALL of these facts?

Thin strands of glass that carry light pulses.

Very fast and good over long distances.

Not affected by electrical interference.

Used in LANs and in undersea (submarine) cables.

Fiber-optic cable.

Which term matches ALL of these facts?

A wireless media type that sends data through the air using invisible waves. Wi-Fi uses this.

A wireless NIC sends this kind of signal.

An access point uses it to connect laptops and phones to the wired network.

It spreads out in all directions, so it does NOT need a clear line of sight like microwave does.

It does NOT go up to space like satellite does.

The same kind of signal is used by a car stereo to play FM stations.

Radio.

Which term matches ALL of these facts?

Wireless and point-to-point.

Two dish antennas, usually on towers or tall buildings, must have a clear line of sight.

Microwave transmission.

Which term matches ALL of these facts?

Wireless media where the signal goes up to space and back down.

Has a longer delay than other media because of the distance.

Example: Starlink internet service.

Satellite transmission.

Which term matches ALL of these facts?

An Application layer address.

Example: www.uw.edu.

Easy for people to understand and remember.

DNS translates it into an IP address.

URL / domain name.

Which term matches ALL of these facts?

A Network layer address. 32 bits (4 bytes) long.

Written in dotted decimal, like 128.192.56.1.

Each of the 4 numbers is 1 byte (0 to 255).

Can be assigned by hand (static) or automatically by DHCP.

Routers use it to make routing decisions. DNS turns a domain name into this.

IP address (IPv4).

Which term matches ALL of these facts?

A Data Link layer address. 48 bits (6 bytes) long, written in hex like 00-0C-00-F5-03-5A.

Built into the Network Interface Card ( NIC )

Never Changes

Example : think of a SSN number or VIN car number

MAC address.

Which term matches ALL of these facts?

______ is a nonprofit organization.

It manages the assignment of IP addresses and domain names.

It approves registrars, like GoDaddy, to sell domain names.

It only has to deal with a few thousand registrars instead of millions of customers.

ICANN (Internet Corporation for Assigned Names and Numbers).

Which term matches ALL of these facts?

A company like GoDaddy that applies to ICANN.

It charges a fee for domain name registration and does the paperwork for you.

This is why domain registration is now commercialized.

Domain name registrar.

Which term matches ALL of these facts?

______ translates human-friendly domain names into machine-friendly IP addresses.

Example: www.uw.edu becomes 128.95.155.134.

Uses port 53, usually over UDP.

Results are cached on your device to speed things up.

Without it, you would need to memorize numbers for every site.

DNS (Domain Name System).

Which term matches ALL of these facts?

It stores DNS records for sites you visited, directly or indirectly.

It makes the next visit faster.

Windows command: ipconfig /displaydns.

Mac command: scutil --dns.

Entries stay until their time to live (TTL) runs out.

DNS cache.

Which term matches ALL of these facts?

The time, in seconds, a DNS entry stays in the cache before it is removed.

Usually 24 hours.

Needed because DNS info can change.

Time to live (TTL).

Which term matches ALL of these facts?

The ______ command sends a DNS request.

A DNS Command

It shows the IP address of a website.

In class you used it to find the IP of petfinder.com.

nslookup.

Which term matches ALL of these facts?

A 2-byte number that identifies an application.

• which app on that computer is this related to

The transport layer uses it to deliver data to the right app.

HTTP = 80. SMTP = 25. DNS = 53.

Each TCP and UDP header has a source and a destination one.

Port number.

Which term matches ALL of these facts?

Transport layer function #1.

Receives data from, and gives data to, the right application.

Uses port numbers.

Linking to the application layer.

Which term matches ALL of these facts?

Transport layer function #2.

Breaks large data into smaller pieces and puts them back together at the destination.

The application layer sees the message as one block of data.

Pieces may go to the app as they arrive (web pages) or after all arrive (email).

Segmenting.

Which term matches ALL of these facts?

Transport layer function #3.

A conversation between two computers, like a virtual circuit.

Using it is called connection-oriented messaging (TCP).

Not using it is connectionless messaging (UDP).

Gives reliable end-to-end connections.

Session management

Which term matches ALL of these facts?

Opens a TCP connection.

SYN, then SYN-ACK, then ACK.

Step 1: "let's connect."

Step 2: "OK."

Step 3: "confirmed.".

The Maximum Segment Size is negotiated during it.

Happens before any HTTP request is sent.

TCP 3-way handshake.

Which term matches ALL of these facts?

The most common transport layer protocol.

Connection-oriented (opens with a 3-way handshake).

Breaks messages into many segments and numbers them.

Resends segments when it gets a NACK. Reliable.

Header is 20 to 24 bytes. Used by HTTP and SMTP.

TCP (Transmission Control Protocol).

Which term matches ALL of these facts?

Connectionless: no handshake, no session.

The whole message must fit in one segment.

Small header (8 bytes) with no error checking.

Much faster. Used for time-sensitive data, control messages, and DNS address requests.

Still part of the TCP/IP world.

UDP (User Datagram Protocol).

Which term matches ALL of these facts?

The largest amount of data in one TCP segment.

Negotiated during the TCP handshake.

Depends on the network and data link layer protocols.

Example: 1,500-byte Ethernet data minus 20-byte TCP and 20-byte IP headers = 1,460 bytes.

Maximum Segment Size (MSS).

Which term matches ALL of these facts?

A negative acknowledgment in TCP.

Tells the sender a segment was not received correctly.

That segment gets sent again.

NACK.

Which term matches ALL of these facts?

Software that captures and inspects network packets.

Used to troubleshoot networks, check security, test apps, and learn protocols.

In class you used it to look at DNS queries and SMTP email.

Available in the Foster virtual lab.

Wireshark.

Which term matches ALL of these facts?

The main network layer protocol.

Responsible for addressing and routing packets.

One TCP or UDP segment goes inside one of its packets.

It starts ARP requests when needed.

Its header has the source and destination address and a hop limit.

IP (Internet Protocol).

Which term matches ALL of these facts?

A permanent IP address.

Set by hand.

Any change needs manual configuration.

The DNS server, subnet mask, and default gateway must also be set by hand.

Static IP assignment.

Which term matches ALL of these facts?

A server leases an IP address to a computer for a set time.

The client broadcasts its MAC address and asks for an IP.

Also gives the DNS server, subnet mask, and default gateway.

Lets addresses be reused, so an ISP can serve more customers than it has IPs.

DHCP (Dynamic Host Configuration Protocol) / dynamic assignment.

Which term matches ALL of these facts?

Translating between network layer addresses and other addresses.

Uses DNS to look up IP when you only have URL name

Examples: DNS (name to IP) and ARP (IP to MAC).

Part of the network layer's addressing function.

Address resolution.

Which term matches ALL of these facts?

The process of deciding the path a message takes from sender to receiver.

One of the network layer's 2 main functions.

using ______ tables to pick the path to the destination when you already have its IP address

Done by routers using routing tables.

Can be centralized or decentralized.

Routing.

Which term matches ALL of these facts?

Used to make routing decisions.

Tells the router which path to send each packet on

like a cheat sheet of directions

Shows which path (interface) to send a packet on to reach a destination.

Kept by every computer that makes routing decisions.

Each router keeps its own.

Routing table.

Which term matches ALL of these facts?

a switch connects devices inside one network

A _______ connects different networks together.

Found at the edge of subnets and connects them together.

Functions: determine path, transmit packets, connect different devices and protocols.

Has a CPU, memory, ports, and an OS.

Has NO disk drive, monitor, keyboard, or mouse.

Layer 3 device that uses IP addresses.

Router.

Which term matches ALL of these facts?

The router that leaves your subnet.

Your network’s exit door

Its the router your computer sends everything to when the destination is outside your subnet

Messages to computers outside your subnet go here first.

DHCP tells your computer this device's IP address.

Its MAC address is in your ARP cache, and it is different from your computer's MAC.

Default gateway.

Which term matches ALL of these facts?

Routing decisions are made by one central computer.

“One boss decides the path for everyone”

Used on small, mainframe-based networks.

Centralized routing.

Which term matches ALL of these facts?

every router decides the path on its own.

Ex. Like using a GPS

Nodes must share info to build their routing tables.

Used by the Internet.

Splits into static and dynamic routing.

Decentralized routing.

Which term matches ALL of these facts?

A type of decentralized routing.

Uses fixed routing tables made by network managers.

managers set the directions by hand.

Tables change only when computers are added or removed.

For simple networks with few routing options that rarely change.

Static routing.

Which term matches ALL of these facts?

A type of decentralized routing.

Routing tables at each node update automatically.

Based on info about conditions shared between routing devices.

Splits into distance vector and link state.

Dynamic routing.

Which term matches ALL of these facts?

Picks the route with the LEAST number of hops.

Used by RIP (Routing Information Protocol).

Example: from A to G, it picks A-B-C-G.

Simple, but ignores congestion and speed.

Distance vector routing.

Which term matches ALL of these facts?

Uses many types of info to pick a route: hops, congestion, circuit speed.

More sophisticated.

Each node shares its info regularly to keep everyone up to date.

Gives more reliable, up-to-date paths.

Used by OSPF (Open Shortest Path First).

Link state routing.

Which term matches ALL of these facts?

One jump of a packet from one node to the next.

The count is kept in the packet header.

A packet with too many is thrown away.

Distance vector routing counts these.

Hop.

Which term matches ALL of these facts?

A LOGICAL group of computers that can talk to each other directly.

Usually each LAN is a separate one.

Gives better security and speed.

Makes network management simpler.

Defined by IP addresses, not by wires.

Subnet.

Which term matches ALL of these facts?

The rule that defines a subnet.

Written as X.X.X.X, where each X is 8 bits.

Example: 255.255.255.0 = 11111111.11111111.11111111.00000000.

Two IPs are in the same subnet if they match in every bit where this has a 1.

A computer uses it to decide: send directly, or send to the gateway?

Subnet mask.

Which term matches ALL of these facts?

Excel function that turns binary into decimal.

BIN2DEC.

Which term matches ALL of these facts?

Also called a network card or network adapter.

A physical part inside your device that connects it to the network.

Wired kind connects the computer to a network cable.

Wireless kind sends a radio signal from the computer.

Layer 2 (data link) device.

Has its own MAC address.

One of the 5 LAN components.

the _______ is the car, and the MAC address is its license plate

NIC (Network Interface Card). Don't mix up with: Access point (connects wireless devices to the wired LAN).

Which term matches ALL of these facts?

Your computer's own IP address.

Your subnet mask.

Your default gateway's IP address.

Your DNS server's IP address.

DHCP usually gives you all 4.

The minimum info required on a TCP/IP network.

Which term matches ALL of these facts?

The client already knows the server's IP address.

It uses the subnet mask to check if the server is in its subnet.

If not, it sends the message to the gateway (router).

It finds the gateway's MAC in its ARP cache, or sends an ARP request.

TCP opens a connection with SYN before the HTTP request.

TCP/IP 'known address' example.

Which term matches ALL of these facts?

The client does NOT know the server's IP address.

It first sends a DNS request (over UDP) to the DNS server.

The DNS server replies with the IP address.

After that, it works just like the known address example.

TCP/IP 'unknown address' example.

Which term matches ALL of these facts?

The highest possible layer being used by a router to pass along a message

At routers, the message only goes up to this layer and no higher. Physical, then data link, then this one.

Routers only need the IP address to choose the next hop.

The Network layer ( layer 3 )

Which term matches ALL of these facts?

these two layers used ONLY at the sending and receiving computers.

routers never use these layers

Transport and Application layers.

Which term matches ALL of these facts?

Benefit: each layer does one job.

You can change one layer without changing the others.

Different vendors can build different layers.

Downside: each header adds overhead, so it can be slower.

Why we use layers.

Which term matches ALL of these facts?

Information sharing, which improves decision making.

Resource sharing, like printers.

Software sharing (per-seat licenses on a server).

Easier device management and software updates.

Reasons to use a LAN.

Which term matches ALL of these facts?

Network operating system.

Transmission media.

NICs. - Network Interface Cards

Hubs or switches.

Hosts.

The 5 components of a LAN.

Which term matches ALL of these facts?

Layer 1 device.

Dumb: it does not make decisions.

Links cables and acts as a repeater.

Sends every message to every computer.

Logical topology: bus.

Every computer reads the destination address to see if the frame is for it.

Hub.

Which term matches ALL of these facts?

Usually a layer 2 device.

Only knows ports and MAC addresses.

Sends each frame only to the right port.

Learns MAC addresses by reading the SOURCE address of incoming frames.

Looks up the DESTINATION MAC in its forwarding table.

Logical topology: star.

Switch.

Which term matches ALL of these facts?

A table inside a switch.

Matches each MAC address to a port.

Built by reading the source MAC of incoming frames.

Switch forwarding table.

Which term matches ALL of these facts?

An electronic device that receives a signal and sends it out again.

Lets a signal go farther or get past an obstacle.

Hubs and switches act as these.

Repeater.

Which term matches ALL of these facts?

Logical topology of a hub-based LAN.

All messages flow onto one shared central cable.

Every computer gets every message.

Computers take turns using the shared circuit.

Bus topology.

Which term matches ALL of these facts?

Logical topology of a switch-based LAN.

The switch sends each frame only to the port it is meant for.

Star topology.

Which term matches ALL of these facts?

Gives mobility for devices.

Works where wires are not practical.

No cabling needed.

Helps mobile users in businesses, hospitals, factories, and universities.

Wireless LAN

Which term matches ALL of these facts?

Uses radio waves to connect wireless clients to the wired network.

Takes the place of a hub or switch for wireless devices.

Is also plugged into the wired LAN.

A device must associate with one before sending data.

Designers plan coverage with 50 to 75 foot squares.

connect wireless devices to your network

while a router connects you network to other networks

Access point (AP).

Which term matches ALL of these facts?

Most of these sold for homes are really 3 devices in one.

A router, plus an access point, plus a switch.

People often use the names loosely.

Home Wi-Fi router.

Which term matches ALL of these facts?

A high-speed network that links LANs.

Lets information move between LANs.

Connects to other backbones and WANs.

Usually limited to one building or campus.

Links LANS in one Building or Campus

MAN = Links LANs and __________ across one whole city

Backbone network (BN).

Which term matches ALL of these facts?

Finds the physical (MAC) address that matches an IP address. Results are stored in a table on your computer.

Most messages go to your gateway, so its MAC is usually in this table.

DNS = website name → IP address
____ = IP address → MAC address

ARP (Address Resolution Protocol).

Which term matches ALL of these facts?

Cheapest to install during construction.

Build in room for growth.

Make a cable plan (map).

Put a wiring closet with hubs or switches on each floor.

Wired LAN tips.

Which term matches ALL of these facts?

Connects IT parts within a small, usually privately-owned area.

Usually one subnet.

Smallest network type.

LAN (Local Area Network).

Which term matches ALL of these facts?

A network of LANs and/or backbones.

Limited to one metropolitan (city) area.

Example: a company's central office, branch offices, and factory in one city.

MAN (Metropolitan Area Network).

Which term matches ALL of these facts?

A network of MANs and/or backbones.

Has no geographic boundaries.

Can cover a whole country.

WAN (Wide Area Network).

Which term matches ALL of these facts?

A network of networks.

Like the universe: many independent systems linked together.

No one network owns it.

The Internet.

Which term matches ALL of these facts?

A company that connects you to the Internet.

Comes in Tier 1 (national), Tier 2 (regional), and Tier 3 (local).

Is an autonomous system that shares routing info using BGP (Border Gateway Protocol).

_____ = the company that sells you internet access

IXP = the meeting place where _____ connect and swap traffic

ISP (Internet Service Provider).

Which term matches ALL of these facts?

A place where ISPs connect and exchange data.

Example: the Seattle Internet Exchange (SIX).

IXP (Internet Exchange Point).

Which term matches ALL of these facts?

ISPs at the SAME tier exchanging traffic.

They usually do not charge each other.

_________ = same tier, free exchange

Different tiers = the higher tier charges the lower tier

Peering.

Which term matches ALL of these facts?

The protocol ISPs use to share routing info with each other.

ISPs using it are called autonomous systems.

BGP (Border Gateway Protocol).

Which term matches ALL of these facts?

Undersea cables that carry Internet traffic between continents.

You can see them at submarinecablemap.com.

Submarine cables.

Which term matches ALL of these facts?

Connects your home to the ISP over phone lines.

DSL modem.

Which term matches ALL of these facts?

Connects your home to the ISP over cable TV (coaxial) lines.

Cable modem.

Which term matches ALL of these facts?

Connects the devices in your home network.

Directs traffic between your home network and the Internet.

Uses IP addresses.

NOT the device that talks to the ISP's line. That is the modem.

Router

Which term matches ALL of these facts?

Shows the IP addresses of routers on the path to another computer.

Windows command.

Many networks block it for security, so it doesn't always work.

Ping = how fast

____ = which way

tracert.

Which term matches ALL of these facts?

Sends a small packet to another computer and times the round trip.

“Response Time”

Works with an IP address or a URL.

Not all computers answer it.

Your default gateway answers fastest. Far-away sites take longer.

ping.

Which term matches ALL of these facts?

A network simulator.

Used for Homework 2 to build and test a pretend Internet.

Available in the virtual lab.

Cisco Packet Tracer.

Data is physically transmitted from one computer or terminal to another in the ________ layer.

(a) physical

(b) data link

(c) application

(d) transport

(a) physical.

Why: Only the physical layer actually sends the signals.

_________ is the software that controls the network.

(a) Network Control System

(b) Client Operating System

(c) Embedded Operating System

(d) Network Operating System

(d) Network Operating System.

The ________ layer decides when to transmit messages over the media and marks where they start and end.

(a) transport

(b) network

(c) physical

(d) data link

(d) data link.

Why: Controlling the media and framing messages are data link jobs.