Protocols

1. Protocols TCP IP DHCP vs Static IPs ICMP

2. Protocols – What are they? • A set of rules that govern how network devices communicate. • For this assessment you will need to include: • TCP – Transfer Control Protocol • IP – Internet Protocol • DHCP – Dynamic Host Configuration Protocol • ICMP – Internet Control Messaging Protocol

3. TCP/IP - What is it? • It’s made up of two protocols – Transfer Control Protocol (TCP) and Internet Protocol (IP). • Just as the movieclip depicted, think of this protocol the same as sending a package overseas. You walk into the post office; select the type of packaging you want; address it; specify its contents i.e you wouldn’t be allowed to send hazardous material; Its then sent on a plane and delivered to its destination. • This in a very simplistic view is what TCP/IP does to data or “packets” on a LAN whether it be you browsing the Internet or printing a file. TCP/IP is critical to allow two devices to “communicate”.

4. TCP/IP Model – 4 layers: • Remember them by saying TCP/IP comes in A-TIN • Gets the package ready for sending. Flow of data packets

5. Transfer Control Protocol - TCP • Ensures your package (packet) arrives safely to its destination. • For excellence, explain how it keeps packets safe, what kind of error checking happens that doesn’t exist with its competitor – UDP.

6. Internet Protocol - IP • Responsible for packaging your parcel (packet). • Packets are made up of:

7. IP Addressing: • A unique number (similar to your home address) given to any network device (e.g printer or computer) attached to the LAN. • Has 4 values separated by a dot. • Each values ranges from 0-255 • There are “local” addresses and “Internet” addresses. Local IPs usually start with 192. or 10. For merit, explain what is meant by an IP address being 32bit. For excellence, discuss IPv4 and why IPv6 had to be created.

8. IP Addressing… • No two computers can have the same address on a LAN! • Example – on your computer go down to Start and type cmd then hit Enter. • In the black screen type ipconfig and hit enter. What is your computers unique address? NOTE: For excellence, discuss the “parts” of an IP address e.g. Network and Host

9. Network Interface Cards: • All Network Interface Cards (NICs)need 2 unique addresses: • One is a Physical address - MAC Address (comes with hardware)

10. Logical Network Connections: • The other, a logical address called an IP address that you assign manually or automatically. You choose. • Remember every NIC or network device needs its own IP to communicate on the LAN, e.g. printer NAS box, laptop, computer, server, router Do the following and write your Computers IP address: Go down to Start and type cmdand click OK. Type ipconfigand hit Enter.

11. Static vs DHCP: • Static – is when you manually assign the IP address to your PC. • You would use this on a peer to peer because there are only a small number of devices/NICs to manage. Right click on Network Places, go into the properties and then again into the TCP/IP properties to view this configuration.

12. Dynamic Host Configuration Protocol (DHCP): • DHCP – is the opposite to static • This is when a DHCP server automatically assigns the IP address to your NIC. • Normally done by Router or a Server. • Would be used on a client/ Server LAN because the number of NICs increase and make it difficult to manage statically. • Exists for ease of administration on larger LANs because a database is maintained. Repeat the IP address steps but type ipconfig /all instead. What is the DHCP Server IP?

13. Internet Control Messaging Protocol (ICMP): • Error diagnostics tool e.g. ping can tell you if a device is “on” the network (reply from…) or not (request timed out). • Required on an IP network. Repeat the IP address steps but type ping ipaddress of gateway instead and hit Enter. What information do you get back?