TCP/IP

Switches vs Hubs

You would expect clients on the same LAN to have symmetric bandwidth.

Router

Which layer do port addresses live at?

If layer 1 doesn't work, then layer 3 won't work even if it is configured properly.

SFTP allowed us to

Multicast is to every computer

-c command does what

-r

free -mh

what does netstat do

Two workstations can be on the same physical network and still not be able to ping each other.

what is HTTP for

ln -s does what

what is subnetting

The standard size of of the data payload in an Ethernet frame is 1500 bytes

What is SSH for

bin

Broadcast is to everyone

what is the very first IP address for

Layer 3 directing data packets between different networks by using IP addresses to determine the best route to send data

ARP is a protocol that needs to utilize broadcast packets to all hosts in the LAN to get some information.

ssh does what(secure shell)

Which protocol maps names to IP addresses?

htop

ss -plunt does what on Ubuntu

Which IP would you get if you are set to receive a dynamic address, but no DHCP servers are available?

ufw command

Which device connects multiple computers together in a LAN?

bandwidth vs latency vs jitter

Today, you will see about 50% hubs and 50% switches in businesses needing to have networks.

How does a switch work that makes it more special than a hub.

Unicast is to one computer

Special Ip Address: 127.0.0.1 , 0.0.0.0 , APIPA. all special IP addresses

What is the localhost address?

who and whoami

Wireshark, you can filter away packets so you can find the precise packets that you are looking for during a analysis

QUIC

A DNS record can map a name to a public IP address, but not to a private IP address.

df -h

What record type do we use to map an address to an IPv4 address?

DORA

Every time a TCP connection is made something happens first. 

Images get broken down into multiple pieces before they are sent. Word documents, text files, and similar do not

what is the very last address in a range of IP addresses for

Layer 1 is physical. it includes lights, radio waves and hubs

sbin

A docker container can include a website with the appropriate software to host the website.

Layer 4 things are called __

/24 is a subnetting mask that is what size

Layer 3 we think about Ethernet frames.

UDP is a protocol that lives at layer 2

10.x.x.x is private, 172.16-31.x.x is private, 192.168.x.x is private

-s command does what

DNS

Layer 7 is user applications

you have a file named dog.html in a folder named f which is in a folder named g at the top of your webroot. Access where

Windows Remote Desktop, a web server, and SSH protocols can all listen on the same port, time and computer

ff:ff:ff:ff:ff:ff is a special MAC address that will do what?

Half Duplex vs Full Duplex

How do you think people most typically login to a server via SSH?

/24 = 255.255.255.0 subnet mask

what does ss do

Containers in Docker are the same as VMs in VirtualBox.

DHCP

what is HTTPS for

SCP does what

There are around 65000 ports available on each computer.

TCP vs UDP

what does NAT do

Layer 4 is transporting pakcets and data between a network

n is what

UDP does not do the three-way handshake, but TCP does.

-ss does what

SFTP does what

1.1.1.1 and 8.8.8.8 are public DNS servers for use by all. Google and Cloudflare

TCP(Transmission Control Protocol)

var is what

Layer 2 is data

iperf3

ARP address resolution protocol that broadcasts IP to get MAC

UDP and TCP are both considered reliable protocols.

During a single bandwidth test using iperf3 you can only test the upload and download speed from host to another host.