Network Types
Confined to a single geographical location, nodes connected by cable or short-range wireless.
What is a LAN?
Break the main trunk cable in this topology and the entire network fails.
What is a bus topology?
Transmits & receives the actual signals that represent bits.
What is Layer 1, Physical?
A switch operates at this layer.
What is Layer 2?
Uses a three-way handshake, tracks packets, resends lost data, and reassembles in order.
What is TCP?
A LAN built for roughly one to ten users in a home or compact workspace.
What is a SOHO network?
HTTP, which serves web pages with no encryption.
What is port 80?
Links buildings across a city or a college campus.
What is a MAN?
Everything runs through one central node: simple troubleshooting, single point of failure.
What is a star topology?
Node-to-node delivery on the same local network using MAC addresses.
What is Layer 2, Data Link?
A router operates at this layer.
What is Layer 3?
A live voice call uses this instead, because speed matters more than perfection.
What is UDP?
Inside a SOHO router; the part that hands every device that connects its own IP address.
What is the DHCP server?
Links a main office to branch offices in three other states over leased provider connections.
What is a WAN?
Same physical shape as a star, but used to connect other networks rather than just one LAN.
What is hub-and-spoke?
Routing best path across different networks using IP addresses.
What is Layer 3, Network?
A hub operates here, because it is a multiport repeater that copies everything out every port.
What is Layer 1?
What data is called at Layer 4, once TCP or UDP splits it up
What is a segment?
Inside a SOHO router, the part that operates at Layer 1, Physical.
What is the wireless access point?
SSH, which gives encrypted access to a command line.
What is port 22?
Private; Uses the same technology as the Internet; restricted to one organization's own members.
What is an intranet?
Redundancy is excellent because if one link dies there is always another route.
What is a full mesh?
Splits data into segments and uses ports to direct data to the right application.
What is Layer 4, Transport?
What data is called at the Data Link layer as it travels down the stack.
What is a frame?
It has no port number and reports on the network itself rather than serving an application.
What is ICMP?
Where the provider's cabling enters the building.
What is the demarcation point?
RDP, which controls another computer's desktop remotely.
What is port 3389?
The portion of a private network a company opens to specific vendors through a login portal.
What is an extranet?
What switches, routers, and access points are called, as opposed to end systems.
What are intermediate nodes?
Translating, compressing, or encrypting data so the application layer can read it.
What is Layer 6, Presentation?
Stripping the headers back off as data moves up the layers on the receiving machine.
What is decapsulation?
In the four-layer TCP/IP model, the Link layer covers these OSI layers.
What are Layers 1 & 2?
The command that shows your IP address, subnet mask, default gateway, DNS servers, and MAC address.
What is ipconfig /all?
DHCP, which hands out IP addresses automatically.
What are ports 67 and 68?