IP & Mac address

Let's learn about how ​IP addresses are used to communicate over a network. ​IP stands for internet protocol. ​An internet protocol address, or IP address, is ​a unique string of characters that identifies ​a location of a device on the internet. ​Each device on the internet has a unique IP address, ​just like every house on a street ​has its own mailing address. ​There are two types of IP addresses: ​IP version 4, or IPv4, ​and IP version 6, or IPv6. ​Let's look at examples of an IPv4 address. ​IPv4 addresses are written as four, 1, ​2, or 3-digit numbers separated by a decimal point. 

​In the early days of the internet, ​IP addresses were all ​IPV4. But as the use of the internet grew, ​all the IPv4 addresses started to get ​used up, so IPv6 was developed. ​IPv6 addresses are made up of 32 characters. ​The length of the IPv6 address ​will allow for more devices to be connected ​to the internet without running out of ​addresses as quickly as IPv4. ​IP addresses can be either public or private. ​Your internet service provider assigns ​a public IP address that is ​connected to your geographic location. ​When network communications goes ​out from your device on the internet, ​they all have the same public-facing address. 

​Just like all the roommates in ​one home share the same mailing address, ​all the devices on a network share ​the same public-facing IP address. ​Private IP addresses are only seen ​by other devices on the same local network. ​This means that all the devices on ​your home network can communicate with each other ​using unique IP addresses ​that the rest of the internet can't see. ​Another kind of address used in ​network communications is called a MAC address. ​A MAC address is ​a unique alphanumeric identifier that is ​assigned to each physical device on a network. ​When a switch receives a data packet, ​it reads the MAC address of ​the destination device and maps it to a port. ​It then keeps this information in a MAC address table. 

​Think of the MAC address table ​like an address book that the switch ​uses to direct data packets to the appropriate device. ​In this video, you learned about ​IP version 4 and IP version 6 addresses. ​You learned how IP and MAC addresses are used in ​network communication and the difference ​between a public and a private IP address.