1.8 KiB
1.8 KiB
id, aliases, tags
| id | aliases | tags | |
|---|---|---|---|
| 07. IPv4 Addressing (Part 1) |
|
IPv4 Addressing (Part 1)
OSI Model
- Provides connectivity between end hosts on different networks (ie. outside of the LAN)
- Provides logical addressing IP addresses
- Provides path selection between source and destination
- Routers operate at Layer 3
IPv4 Header
IP addresses are 32 bits long
Class A 192.168.1.254/24 192.168.1. = network portion (part of the same network) 254 = host portion (different machine)
Class B 154.78.111.32/16 154.78 = network portion 111.32 = host portion
Class C 12.128.151.23/8 12 = network portion 128.151.23 = host portion
IPV4 address classes
| Class | First octet | numeric range | Prefix Length |
|---|---|---|---|
| A | 0xxxxxxxx | 0-127 | /8 |
| B | 10xxxxxxx | 128-191 | /16 |
| C | 110xxxxxx | 192-223 | /24 |
| D | 1110xxxxx | 224-239 | |
| E | 1111xxxxx | 240-255 |
class D are reserverd for Multicast addresses class E are reserved for expermital end of the class A is 126 127 are reserved for loopback addresses
Loopback addresses
- Address range 127.0.0.0 - 127.255.255.255
- Used to test the 'network stack' (think OSI, TCP/IP model) on local device
Netmask
Class A: /8 255.0.0.0 Class B: /16 255.255.0.0 Class C: /24 255.255.255.0
Host portion of the address is all 0's = Network Address the netowrk address cannot be assigned to a host
Host portion of the address is all 1's = Broadcast address Address The Broadcast address cannot be assigned to a host
Review
- Network portion / host portion of IPv4 address
- IPv4 classes
- Prefix lengths / netmasks
- Network address / broadcast addresses