DHCP is often used for hosts to automatically assign IP addresses and uses 4 different packets to do so. Since a host doesn’t have an IP address to start with, we use...
In this lesson, we’ll take a look at how you can secure user mode and privileged (enable) mode. By default, there is no authentication required. If you connect a Cisco...
Most Cisco devices (including routers and switches) use a CLI (Command Line Interface) to configure the network device. The CLI is an interface, based on text. You type...
DNS (Domain Name System) is a network protocol that we use to find the IP addresses of hostnames. Computers use IP addresses but for us humans, it’s more convenient to...
ICMP (Internet Control Message Protocol) is a network protocol used for diagnostics and network management. A good example is the “ping” utility which uses an ICMP...
TCP (Transmission Control Protocol) is a connection oriented protocol which means that we keep track of how much data has been transmitted. The sender will transmit some...
TCP (Transmission Control Protocol) is a reliable transport protocol as it establishes a connection before sending any data and everything that it sends is acknowledged...
In this lesson we are going to take a look at our transport protocols TCP and UDP. If you know about IP and IP packets you know that we require a transport protocol to...
If you learned about the OSI Model and encapsulation / decapsulation you know that when two computers on the LAN want to communicate with each other the following will...
The IPv4 packet header has quite some fields. In this lesson we’ll take a look at them and I’ll explain what everything is used for. Take a look at this picture: Let’s...
