IP address range Question

[username214]

Greetings!

I am trying to come up with my own IP address scheme for my small home network as practice for my upcoming Network+ exam. I have a few questions.. The obvious choice is a Class C address because I am only connecting about six hosts. This gives me a range of 192 - 223. I know standard practice is to use the 192.168.0.0, however I am looking to choose a different network address.

Say for example, I wanted to use 210.023.020.0.... Would this work? It is within the range of the class C, so by my understanding it SHOULD work and give me 254 possible hosts...

Secondly, reading through my study material there is a whole section of RFC 1918 which outlines non-routable Private IP addresses. For Class C, the range is 192.168.0.0 - 192.168.255.255. Does that mean the example address I gave of 210.023.020.0 is a routable to the public internet, and therefore less secure than choosing one of the networks within the Private IP Range?

I realize this might be a easy to the networking gurus out there, but I am studying for this on my own, and I really don't have anyone I can pose these kind of questions to. Any help would be great! This forum helped me get my A+ and I lurk quite often shifting through various topics. This is one of the best communities I've found online. Anyways, looking forward to some replies!

 

[bill001g]

The concept of class a,b,c etc is outdated. You can use a /24 subnet on any so called class. You could also use 192.0.0.0/8 if you really wanted to.

In a home network it does not matter what IP you use, you could use any companies ip. Your IP will always be the one that is assigned by your ISP and your router will NAT any internal address to that single IP. The reason you do not use public ones is that you run the risk of duplicating a site on the internet. It will not hurt anything on the internet but your machines would not have access because they would send the traffic to the machine inside your network.

The only way to actually use real routable internet addresses would be to have a commercial internet connection. Even then only a extremely large company can do this because of the difficulty in getting blocks of IP addresses. Still the ISP guard against someone doing something stupid and only allow you advertise the blocks that have been allocated to your company. So even if you attempted to advertise out a different block the ISP would not accept you as a source for that block.

Do not spend a lot of money on certifications that are not well respected. There are tons of people with CCNA which is many times harder than any of the other low level network certs. Even the CCNA has lost a lot of its value because so many people have it.

 

[Ralston18]

My suggestion is to simply try 210.023.020.0.... Or other address ranges you wish to experiment with.

By experimenting and trying you will have successes and failures. You will learn from both.

Also this link:

http://serverfault.com/questions/725666/when-to-use-routable-vs-non-routable-ip-addresses

Nothing specific about that link per se. Just one of the resulting links from googling "routable IP addresses".

There are other links that you can pick and chose from for more information and background.

And IP address "classes" are phasing away in favor of CIDR. No intention of opening debates or other discussions about that - just felt compelled to mention the evolution......

 

[gbb0330]

the following ranges are designated for internal networks:
192.168.0.0 - 192.168.255.255 (65,536 IP addresses)
172.16.0.0 - 172.31.255.255 (1,048,576 IP addresses)
10.0.0.0 - 10.255.255.255 (16,777,216 IP addresses)

anything else, like 210.023.020.0 may cause routing issues because someone's public IP address may be in that range.

 

[McHenryB]

I know standard practice is to use the 192.168.0.0, however I am looking to choose a different network address.

TBH, if you are considering using a non-private address range - without having it assigned to you - then you don't deserve to pass your network exam. What is wrong with using one of the address ranges that is dedicated to this usage?

Abide by the RFCs.