netconnect.tar.gz

This course is a quick guide for understanding the internet protocol standard IPv4, including its packet structure, subnetting, and address configuration on hosts and routers. It also discusses the sixth version, IPv6, and its addressing scheme, subnetting, and coexistence with IPv4.

A Quick Guide for IP Subnetting

# Packet transmission
In IPv6, there is no such thing as _broadcast message_ types. Broadcast traffic has been replaced with multicast.
 
If we think about it, that sounds pretty logical. If we want to send traffic to a specific group of devices in our network (the multicast), then we can use a similar message type and send it to all the devices connected to our network. All devices will be gathered in a specific group.

Now, let’s look at the other ways we can send IPv6 traffic:

- **Unicast** (one to one):  It is used when sending a packet directly from one device to another specific device in a network, for example, a phone call between two persons.

- **Multicast** (one to many): It is used when sending a packet to a group of recipients in the network, for example, an email sent to a mailing list.


- **Anycast** (one to closest): If we want to go to google.com, we must first translate the name into an IP address. To do so, we need a DNS server. Because there are multiple DNS servers in the world, an anycast message will be sent to the closest server to our location. This way the waiting time is lower and our browsing experience are faster.

# IPv6 subnetting 
IPv6 has enough addresses available and the size of a network does not matter. We’ll often see IPv6 networks that have a `/64`, `/80`, `/96`, or other masks.

Now let’s see what a `/64` network looks like.

`2002:ABCD:1234:9FD8::/64`

This address is excellent for learning about subnetting. The `/64`, in this case, refers to the fact that the first 64 bits (the first four fields) _do not change._

We can assign a mask of `/80` to any network we want. Let’s assume that we need four networks, each with a different number of required IP addresses (all fitting into `/80`).
* 1st network: `2002:ABCD:1234:9FD8:0000::/80` (or `2002:ABCD:1234:9FD8::/80`)
* 2nd network: `2002:ABCD:1234:9FD8:0001::/80` (or `2002:ABCD:1234:9FD8:1::/80`)
* 3rd network: `2002:ABCD:1234:9FD8:0002::/80` (or `2002:ABCD:1234:9FD8:2::/80`)
* 4th network: `2002:ABCD:1234:9FD8:0003::/80` (or `2002:ABCD:1234:9FD8:3::/80`)

To get the next network, we’ll look at the fifth field and just add 1. 
 
And that’s it! It doesn’t make any sense to overstress with subnetting based on how many IP addresses we need in our networks. All we have to do is take the IPv6 address space provided to us by our ISPs and break it down into smaller networks (with a mask of `/64`, `/80`, `/89`, and so on).

The next step is to determine the number of networks we need. Finally, we’ll divide the big network (provided by our ISP) into smaller ones.

In other words, if we receive a `/64` network, then we’ll use `/80` for our smaller networks.


Learn about packet transmission ways and IPv6 subnetting.

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Packet Transmission and Subnetting in IPv6

Packet transmission