What Is Networking

What is the internet?

• Internet = networks joined together

• ARPANET = first iteration of the internet.

• World-Wide-Web (1989 by Tim Berners-Lee), the internet is no longer used as a repository for storing and sharing information.

• A network can be one of the two:

  • Private network
  • Public network

Questions

1. Who invented the World Wide Web?

R: Tim Berners-Lee

Identifying Devices On A Network

• Devices are identifiable through similar ways as humans (name, fingerprint), one being changeable and the other permeable:

  • An IP address
  • A MAC (Media Access Control) Address

IP (Internet Protocol) Adresses

• IP (Internet Protocol) is divided into four octets.

• An IP address cannot be active simultaneously more than once in the same network.

• Devices can either be on a private or a public network. Their IP differs.

• A public address is used to identify the device on the internet

• A private address is used to identify the device amongst other devices.

• When two devices communicate in the same private network, they will be able to connect to the internet using the same public IP address.

• IPv4 suports 2^32 (4.29 billion) IP addresses and these may not be sufficient for the near future.

• IPv6 supports up to 2^128 (340 trillion-plus) IP addresses and it is more efficient than IPv4.

MAC Addresses (Media Access Control)

• unique address assigned at the factory built on the device’s physical network interface.

• 12 character hexadecimal number

• split into two and separated by a colon:

  • first 6: vendor who built the network inteface.

  • last 6: unique address of the network interface.

• MAC addresses can be faked (spoofed), when a device pretends to identify as another using its MAC address.

• E.g.: A firewall is configured to allow any communication going to and from the MAC address of the administrator. If a device were to pretend or “spoof” this MAC address, the firewall would now think that it is receiving communication from the administrator when it isn’t.

• This is used especially in places like cafes, coffee shops and hotels.

Questions

1. What does the term “IP” stand for?

R: Internet Protocol

1. What is each section of an IP address called?

R: Octet

1. How many sections does an IP address have?

R: 4

1. Deploy the interactive lab and spoof your MAC address to access the site. What is the flag?

R: THM{YOU_GOT_ON_TRYHACKME}

Ping (ICMP)

• Ping uses ICMP (Internet Control Message Protocol) packets to determine the performance of a connection betwewn devices, if it exists or perhaps if it is reliable.

• The time measuring is done usings ICMP’s echo packet and then ICMP’s echo reply from the target device.

Questions

1. What protocol does ping use?

R: ICMP

1. What is the syntax to Ping 10.10.10.10?

R: ping 10.10.10.10

1. What flag do you get when you ping 8.8.8.8?

R: THM{I_PINGED_THE_SERVER}