Networks

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10-Sep-22 (Created: 10-Sep-22) | More in 'azure'

Networks

satya - 9/6/2022, 12:25:32 PM

A good way to visualize what networks, hosts, and routers are

satya - 9/6/2022, 12:26:35 PM

This is taken from: Introduction to networks

: https://cs.lmu.edu/~ray/notes/netsandinets/

satya - 9/6/2022, 12:27:49 PM

Keys

1. Network is a collection of hosts with their addresses

2. A router sits on two networks and and allows a unified address space

3. A network has an address

4. A host has an address

5. ip (network address + host address)

satya - 9/6/2022, 12:30:44 PM

Notice how the routers have addresses


Network1
  hosts
    1/1 router (also has 2/3 - from network 2, 3rd host)
    1/2 router (also has 3/1)

Network2
.. etc

satya - 9/6/2022, 2:11:53 PM

Azure networks learning track

satya - 9/6/2022, 2:12:17 PM

What does a network or a subnetwork address, cidr look like?

Search for: What does a network or a subnetwork address, cidr look like?

satya - 9/6/2022, 2:28:49 PM

Classes


Starting with:
class A: 0 to 127
B: 128 to 191
C: 192 to 223

D and E I am not going to talk about

127.*.*.* loop backs

Private networks
********************
class A: 10.x 
Class B: 172.16.x to 172.31.x
Class C: 192.168.x

Network vs Host
******************
Class C: 
  network (a.b.c) host (.d) mask (255.255.255)
  in CIDR (192.168.0.0/24)

class A: mask (255.0.0.0) 
    First byte network
    3 bytes hosts
    CIDR 8

class B: mask (255.255.0.0)
    First 2 bytes network
    second 2 bytes hosts
    CIDR (16)

class C: mask(255.255.255.0)
   First 3 bytes network
   Last byte hosts
   CIDR (24)

satya - 9/6/2022, 2:37:08 PM

Call outs on classes and masks

1. Class is always determined by the first byte alone!!

2. Various ranges in that "first byte" will tell you the class

3. Multiple bytes take part in masks for each class

4. Knowing the first byte, you can tell which part of the address is the network and which part the host (via the mask). That first byte will tell you which mask to apply

satya - 9/6/2022, 2:45:36 PM

Understand CIDR and subnets: some history

satya - 9/6/2022, 2:49:33 PM

Quick summary of CIDR

1. Classes assume subnets are fixed in variety based on each class and their respective number of hosts

2. CIDR introduced for variable number of subnets and hosts

3. CIDR: Classless Inter-domain routing.

4. Introduced in 1993

satya - 9/10/2022, 12:50:45 PM

Questions

1. Routers and how they work

2. DNS servers, and how are they delegated