Need explanation on IP address result

private network ip ranges rfc 1918

When I ran "ipconfig" command on my workstation, the result I obtained is as shown in the picture (ipconfigResult.jpg). The result shows two different IP addresses i> 100.100.100.218 and ii>192.168.51.1. Can a single computer have two IP addresses. My workstation is connected to a LAN network. Could anyone please explain where I'm confused.....!

Regards
M

Yes, it's possible to have several ip addresses - One is main and others are aliases.

Hello,

As Dallas-Iv said, it's possible. I think whe can help you if you post what is your operating system and the result of "ipconfig /all".

The /all parameter said to the ipconfig program to show all the information about your active nic's and configuration.

By,

GuillerMo (AR)

gdaporta, i'm using Windows XP SP2 and the result of ipconfig/all is shown in the figure. Please let me know what you find out from the result.

M

Hello,

You have assigned two IP Address to your network interface card. You must remove one of them if you are not using it.
For remove one of the two IP address follow the netx steps:

1- Got to: Start -> Configuration -> Network Connections

2- Identify your network connection and open the properties windows (right mouse click and select "Properties" from the list of actions).

3- Select the TCP/IP protocol and then click on the "Properties" button.

4- In the bottom of the TCP/IP properties tab you must have a button of "Advanced Properties", click on it.

5- In the first block you must have two ip addesses, like I show you in the attachment image (My windows XP is in spanish, but is the same):



Select the undesired IP address and then click on the remove button. Then click OK to all the windows and maybe you need to restart your computer.

By,

GuillerMo (AR)

Thanks for the reply. I have another query. Why do workstations in LAN have their ip address start with 192.168.X.X?

Regards
M

Go to network connection settings, and remove one of them if u don't want it..

magnetra said:

Thanks for the reply. I have another query. Why do workstations in LAN have their ip address start with 192.168.X.X?

Regards
M

Click to expand...

The IP Addressing have clasess, and on each class there is a reserved blocks of the IP address space for private networks.

In IP terminology the 192.168.0.x is a private network. A private network is an internal (non-Internet) network and not directly with the Internet. This internal network maybe connected to the internet trugh a proxy or a router.

If a device on a private network needs to communicate with other networks, like the internet, needs an equipment to allow the communication. in most cases this equipment is a router and is called gateway.

192.168.0.x is a class C private network. There is another private network available in IP v4:

CLASS A
IP address range: 10.0.0.0 – 10.255.255.255
number of IPs: 16,777,216
Subnet Mask: 0.255.255.255 or /24

CLASS B
IP address range: 172.16.0.0 – 172.31.255.255
number of IPs: 1,048,576
Subnet Mask: 0.0.255.255 or /16

CLASS C
IP address range: 192.168.0.0 – 192.168.255.255
number of IPs: 65,536
Subnet Mask: 0.0.0.255 or /8

The private networks, described in RFC1918 (Request for Comments #1918), has reserved the 192.168.x.x for private networks.

You could obtain RFC1918 at:
https://tools.ietf.org/html/rfc1918

By,

GuillerMo (AR)

CLASS C
IP address range: 192.168.0.0>/b> – 192.168.255.255
number of IPs: 65,536
Subnet Mask: 0.0.0.255 or /8

When you asked, you said 192.168.x.x,and it's a mistake.

Click to expand...

Gdaporta
You've said that class C private network IP ranges from 192.168.0.0>/b> – 192.168.255.255. But in class C only the last octet should vary for the hosts in the network isn't it?

M

magnetra said:

CLASS C
IP address range: 192.168.0.0>/b> – 192.168.255.255
number of IPs: 65,536
Subnet Mask: 0.0.0.255 or /8

Click to expand...

Gdaporta
You've said that class C private network IP ranges from 192.168.0.0>/b> – 192.168.255.255. But in class C only the last octet should vary for the hosts in the network isn't it?

M

Click to expand...

I make a mistake when I said that 192.168.x.x wasn't a private network and I fix it.

CLASS C private networks description is OK. When I said "192.168.0.0 – 192.168.255.255" I was talking about a range or a block, and it range includes hosts and networks.
If take a look at the complete description you could find that the address mask is 0.0.0.255 or /8, so only the last eight bits were used to define the host address, and the other 24 bits were used to define the network address.
When I wrote "192.168.0.0 – 192.168.255.255" I try to said:

192.168.0.x /8 First Class C Private network
192.168.1.x /8 Second Class C Private network
...
...
...
192.168.255.x /8 Last Class C Private network

Do you understand what I am talking about ???

If not, you could take a look at the RFC1918 at h**p://tools.ietf.org/html/rfc1918.

By,

GuillerMo (AR)

I got it. Thanks gdaporta.

M