# IP Address

ip address subnet

/8 Problem

/8 address is worth $200M to 1.5 billion Small number of companies own majority of the addresses.

IPv4 Exhaustion Problem | NAT saves the day.

# IP Address

Very much like mailing and postal service by humans. Whats the composition of an IP address?

Representation in

Decimal format 127.0.0.1
32-bit Binary format, actually used in computer hardwares.

IP address representaion

Simple math, how many total addresses are possible?

32-bit, each bit can have either of 2 values (0|1)

Addresses

# Classful Networking

Classfull Networking

Class C for smaller businesses as there are less number of hosts
Maybe class A for larger corporations
Map of the internet
List of assigned /8 IPv4 address blocks
Internet census, Carna botnet
- Of the 4.3 billion possible IPv4 addresses, Carna Botnet found a total of 1.3 billion addresses in use, including 141 million that were behind a firewall and 729 million that returned reverse domain name system records. The remaining 2.3 billion IPv4 addresses are probably not used.

Carna botnet

# CIDR - Classless Interdomain Routing

Valid CIDR block for 10.0.0.15/20 ?

It represents a range of IPs

10.0.0.15 first starting IP /20 subnet mask
We calculate the last IP address and total number of IPs in CIDR block

last 12-bits are used for IP addressing

How many IPs can be represented by 12-bits

part following / in CIDR notation is subnet mask
CIDR to IPv4 conversion tool
How to calculate first and last IP in CIDR?

# Who Manages all IP address on internet?

Roles of IANA?

Maintains and manages DNS and IP addresses
Multistakeholder model
Ineternet Protocol Address Allocation
The protocol Parameter Registry
TLD - Top Level Domain management system
Country code top level DNS
Timezone Database Management

# Public/Private IPs

Internet

We have smaller networks connected to larger networks to make Internet.

Public IPs are available on the internet, means directly connected to the internet. Its unique all over the world. No other person/organization can have it. For Example, Phone Numbers as analogy

Private IP address are NOT on internet. Whats the range?

Private IP range

If private IP addresses are NOT on internet, then how do we access internet from them?: Private IPs are usually connected to public IP through a router and NAT to connect to internet.

Private IPs works in conjunction with Subnet Mask. Only IP means nothing, cant do much with it alone.

What does a Network Mask do?

Tells all network devices (like routers, hubs, network cards), that this number represents network address and this part represents node address.

Distinguish between network part and host part.

# IAM - Identity Access Management

How to create Policies?: JSON directive format

# AWS Cognito

Decentralized Managed Authentication

# Resources

}

AMAZONAPIGATEWAY(api)

AWSLAMBDA(lambda) {
    LAMBDAFUNCTION(addComments,addComments)
}

AMAZONDYNAMODB(dynamo) {
    TABLE(comments,Comments)
}

}

user - browser

browser -d-> site :1a) get\nstatic\ncontent site ~> logs :1a site .u.> browser :1b browser - js js -r-> comments :2a) get\ncomments comments ..> js :2b