Private IP Addressing

Hi, I'm new here, just starting my network+. I'm fluent with PC repair and maintenance and configuring windows but have a very limited knowledge of networking that doesn't stretch far beyond the home router so decided to take this cert.

Anyway, I was wondering if someone can clarify something for me to help me understand the topic of Private IP Addressing a little bit more.

The book i'm reading states that all private IPs should fall into 3 ranges set by RFC 1918, class A 10.0.0.0 - 10.255.255.255 , class B 172.16.0.0 - 172.31.255.255 and class C 192.168.0.0 - 192.168.255.255, which is fine, I had no problem understanding that, but I decided to be nosey at work today on the corporate network and done a quick ipconfig on my workstation expecting to see one of these addresses. The address that came back to me began 149.209.x.x with gateway of 255.255.255.0 which doesn't fit into any of the above. The gateway address also began with 149.209.x.x

What is my IP.com showed the public address starting with 195. so it didn't come from there. If someone could explain to me where this IP range comes from so I can understand bit more that would be great.

Sorry if i'm jumping ahead or missing something obvious, but its thrown me into confusion.

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Comments

vishnuvardhan

The ip which you are getting is just a public ip address which is running on one device and taking a default route pick up of 255.255.255.0 means there must be some more devices configured with same default gateway , but it cannot be possible as 255.255.255.0 that comes under subnet mask or wild card mask , must be mis configured or have some big issues

HP_Guy

vishnuvardhan wrote: »

The ip which you are getting is just a public ip address which is running on one device and taking a default route pick up of 255.255.255.0 means there must be some more devices configured with same default gateway , but it cannot be possible as 255.255.255.0 that comes under subnet mask or wild card mask , must be mis configured or have some big issues

I suspect the op meant subnet mask, rather than gateway (the first time) as they then go on to say the gateway address also began with 149.209.x.x

cwshellhamer

You can also NAT your public IP address to any private address you want. Since your gateway router translates any private ( 192.168.1.X) address to a public address to go out to the internet. This is why you can set any IP addressing you want on your router at home. You can configure your router to do a 1.1.1.X 255.255.255.0 network and its doesn't care. Your router will translate that 1.1.1.X address back over to your public address assigned to you by your ISP. Almost all home routers are configured for a 192.168.1.x address scheme just for sake of uniformity.

JKWilliamsSr

If you want to see the internal IP address of your machine you need to do ipconfig /all