This is a short post on how and where to find the IP address and static/dynamic status for your Windows 7 machine within your Local Area Network (LAN). If you are using a Linux machine, follow this link:
Every now and then, we need to know something trivial, such as the current IP address of the machine at which we sit. Within limits, this is simple enough to do.
With a pair of useful Terminal Commands at the Windows Command Prompt, we can find the information we need:
Private (internal to our LAN) IP Address of our current computer, and our router:
> ipconfig
Static/Dynamic status of IP Addresses within our LAN:
> arp -a
Current LAN IP Address - Windows:
Open a terminal window using Start Menu (on Windows 7) by typing cmd into the “Search” field:
Open the Start Menu:
Type cmd into the Search field:
Click on the cmd Item Listed Under Programs:
Type ipconfig into the Terminal Window:
After you hit the enter key, the terminal window will fill with a bunch of network-related information. Depending upon your network and machine configuration, the contents of the window may well scroll down until the first few items are no longer in view (as it did here on my machine, visible below). If so, use the scrollbar to move the top of the list following the ipconfig command back into view:
In the section called “Ethernet adapter Local Area Connection”, the item named IPv4 Address represents the current IP address assigned to your machine. In my case, my current machine is assigned the IP Address 192.168.0.100.
Also in the same section, the item named “Default Gateway” represents the private, or internal IP Address of your router. In my case, my router’s internal IP Address is 192.168.0.1.
Both of these represent addresses internal to our Local Area Network, and are not exposed to the internet-at-large. Using the IP Addresses within our LAN allows us to access the other machines on our network (subject to proper permissions, of course).
For the moment, write these two addresses down. In my case:
- The private IP Address of my computer is 192.168.0.100
- the private IP Address of my router is 192.168.0.101
Static or Dynamic IP Assignment?
Note that these addresses are not necessarily static (or, permanent). Routers often assign IP Addresses dynamically. While a given dynamic IP address on your home network is unlikely to change very often, it CAN. In order to check out which type of IP Address(es) we are dealing with, we can execute the arp -a command in our terminal:
Type arp -a into the terminal:
Then hit the Enter Key:
Since I know that my computer’s IP Address on my network is 192.168.0.100, I can find that address in the list displayed in my terminal and see that, indeed, I am using a dynamic IP address. Further, I can see that my router, too, is using a dynamically-assigned IP Address.
On my system, these address assignments are unlikely to change. I have a small, private home network, and it is improbably that circumstances would require my router to assign them differently.
John on Google
This is a short post on how and where to find the IP address and static/dynamic status for your Linux machine within your Local Area Network (LAN). If you are using a Windows machine, follow this link:
Every now and then, we need to know something trivial, such as the current IP address of the machine at which we sit. Within limits, this is simple enough to do. NOTE: These appear to be mostly universal, but I feel compelled to mention that I am assuming a Debian-based Linux here. I am not widely versed on all the various distributions!).
With a pair of useful Commands at the Bash Terminal, we can find the information we need:
Private (internal to our LAN) IP Address of our current computer, and our router:
$ ifconfig
Static/Dynamic status of IP Addresses within our LAN:
$ cat / etc/network/interfaces
Current LAN IP Address - Linux:
Open the Bash terminal and type ifconfig
The hit the Enter Key:
Note in the above that the section of the terminal output we are interested in is eth0. Within that section, we find the item inetaddr:192.168.0.113. This is the internal IP address assigned to our current machine within the Local Area Network (LAN). This address is private to our LAN, and is not exposed to the internet-at-large. Note this address, as it is how you will address this specific machine within the confines of your Local Area Network.
Static or Dynamic IP Assignment?
Note that this and other IP addresses found on our LAN are not necessarily static (or, permanent). Routers often assign IP Addresses dynamically. While a given dynamic IP address on your home network is unlikely to change very often, it CAN. In order to check out which type of IP Address we are dealing with, we can use the cat command in our Bash terminal to examine the contents of the network interfaces configuration file used by our computer. Under Most Debian-based Linux systems, we can do this as follows:
Use cat to open the network interfaces file:
The hit the Enter key:
If what you see is similar to the above, this indicates a dynamic IP assignment (the auto lo is the key phrase here. My Linux box receives a dynamic IP assignment from my home network router, as do most.
If you’re the IP assigned to your machine is static, the output to the terminal window would have looked a little like THIS (I can’t show terminal output here because I do not have a static IP assignment for my Linux Machine):
# The primary network interface
allow-hotplug eth0
iface eth0 inet static
address 10.1.1.20
netmask 255.255.255.0
network 10.1.1.0
broadcast 10.1.1.255
gateway 10.1.1.1
John on Google