The Network Layer - Routing - Non-routable address space

5 important questions on The Network Layer - Routing - Non-routable address space

What does RFC1918 stand for and what does it do?

RFC stands for Request for Comments. In 1996 RFC 1918 was published, and it outlined a number of networks that would be defined as non-routable address space.

What is non-routable address space?

Non-routable address space are ranges of IPs set aside for use by anyone that cannot be routed to. Not every computer connected to the internet needs to be able to communicate with every other computer connected to the internet.  Non-routable address space allows for nodes to communicate with each other on same network.

These IP addresses are reserved for private networks, and interior gateway protocols will route these address spaces within network.

Which are the three ranges of IP addresses that will never be routed anywhere by core routers, as defined by RFC1918?

The three primary ranges of non-routable address space are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
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What does it mean in practice that these three ranges have been defined by the RFC1918?

That means that they belong to no one and that anyone can use them. In fact, since they are separated from the way traffic moves across the internet, there's no limiting to how many people might use these addresses for their internal networks

These ranges are free for anyone to use for their internal networks.
Interior gateway protocols will route these address spaces and they are appropriate for use within an autonomous system.

What are three advantages of non-routable address space?


Advantages :

1. It helps in conserving IPv4 address space.
2. Extra layer of security, since these networks cannot be accessed by exterior gateway routers. So, network is safe from malware and viruses.
3. Data protection and privacy- Since data can be accessed only inside network. It is good for small businesses that handle lot of data and sensitive information.

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