1. IP addresses

IP addresses are a Layer 3/Netweork protocol, Router

inet = IPv4 address -- in decimal notation inet6 = IPv6 address -- hexadecimal notation

┌──(theo㉿DESKTOP-LH5PNJ0)-[~]
└─$ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.25.116.131  netmask 255.255.240.0  broadcast 172.25.127.255
        inet6 fe80::215:5dff:fea8:9707  prefixlen 64  scopeid 0x20<link>
        ether 00:15:5d:a8:97:07  txqueuelen 1000  (Ethernet)
        RX packets 223281  bytes 80667139 (76.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 6146  bytes 501107 (489.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

inet/IPv4 address each section/octet/between the periods -- 1's and 0's is eight bits in total a IPv4 address is made up of 32bits = 8+8+8+8 = 11111111.11111111.11111111.11111111 128 64 32 16 8 4 2 1 = 255 1 1 1 1 1 1 1 1

IPv4 Uses NAT / Network address translation with NAT we assign private IP addresses

Private IP addresses

Network Class	Network Numbers	Network Mask	No. of Networks	No of hosts per Network
Class A	10.0.0.0	255.0.0.0	126	16,646,144
Class B	172.16.0.0 to 172.31.0.0	255.255.0.0	16383	65024
Class C	192.168.0.0 to 192.168.255.255	2,097,151	254	Most common for home and small business
LoopBack	127.0.0.0 to 127.0.0.7	255.255.255.0	---	---

Class A - Most common for big business, Small number of networks, large number of hosts Class B - Class C - Most common for home and small business, Large number of networks, small number of hosts Any IP address outside of these public IP's and loopback are private IP's and up for grabs. most likely already grabbed