HW #2.2 Flashcards
- What is a server? How is it different than a desktop computer?
A server is similar to a computer in structure, except that it is much more powerful; able to handle more data, users, applications and support enterprise-level activities, communications and data transfers.
- What is an IP address?
An IP address is an identifier of computers/devices.
- What is the idea behind DNS? Why would you give a server a domain name?
The purpose of DNS is to translate human-readable domain names into IP addresses. Giving a server a domain name makes it easier for people to access websites and services without needing to remember complex IP addresses.
- How do you display the IP address of your server?
*
hostname -i
- What are the similarities and differences between a hub and a switch?
A hub is an unintelligent device that broadcasts a signal to all devices connected to the hub, whereas a switch can direct traffic to a specific destination. Both a hub and a switch manages data flow and traffic.
- What is the main difference between a hub/switch and a router?
*
The main difference between a hub/switch and a router is that a switch and hub creates and contains a network, whereas a router allows traffic to travel within networks. Think of a switch as a gate to a city, and the router as roads within that city.
- What is the difference between a modem and a router and what does each do?
A modem brings internet into a home and/or business. A router routes and passes internet connection in your devices.
The modem also demodulates incoming analog signals and modulates outgoing digital signals; while routers act as wireless access points.
- What is CPU and what does it do?
CPU is a central processing unit responsible for executing instructions of a program and performing various calculations and operations
- What is the difference between disk space and RAM?
main difference between disk space and RAM is that disk space refers to storage, whereas RAM refers to the amount of memory available to conduct an application.
What is RAM required to do?
RAM is required to run applications.
- What does it mean if you’re low on memory?
It means a computer’s available RAM is running out or being heavily used.
What does it mean if you’re low on disk space?
It means you are running out of “physical” space to store programs or applications.
- What is the command to check storage on the drives on your server?
df -h
- What is the general idea behind a transport protocol?
It’s the method in which data is being transported from server to server. The main ones are UDP and TCP.
- What is the 3-way handshake comprised of, and which transport protocol is it associated with?
3-way handshake = 1. Syn 2. Syn Ack 3. Ack received ; it is associated with TCP
- What is the “Fire and Forget” protocol?
The Fire and Forget protocol is UDP, which is a server that continually bombards another server with data or transmissions without caring whether it is being received.
- Which transport is faster?
UDP because there are no checks.
- Which transport is more secure
TCP, because it validates the receipt of data.
- How do you know what ports are open and listening on your server?
Use ss -tanpu or -tulpn command and then look at state section of information log
- What is ping used for? (Give at least 2 examples)
query whether a server is connected to the internet.
check whether there is a DNS error or a network card failure.
- What is a loopback test for? How do you do it?
A loopback test determines whether your own server is the point of failure, and further helps determine where the failure is coming from. To run a loopback test, you can write in the CLI:
ping 127.0.0.1
or
ping localhost
- How do you verify that DNS resolution is working properly?
ping (Insert Hostname)
- If an IP is reached successfully, but not its domain name, what could be a possible problem?
It’s possible you have the wrong DNS, or the domain name server is down, or the DNS resolver is down.
- How do you test connectivity to the internet?
ping google.com
