It can furthermore be difficulty sometimes to get to the root of the problem, especially if the issue is caused by software and not the user or system administrator.

The free Windows software IP Seizer aids users by displaying IP address and related information about each computer system and device connected to the local computer network.

The portable software can scan local IP ranges for connected devices. Each device found is listed with its IP address, host name, MAC address and Workgroup or domain.

You can enter a start and end IP manually into the program, or use the suggested values for the scan. A click on start checks all IP addresses in the range for connected devices and adds all devices found to the list. Timeouts are set to 100 milliseconds which means that the program checks roughly 10 IP addresses per second. You can reduce the timeout to speed up the the time it takes to check the selected IP range.

The thorough scan mode takes longer to complete but will provide additional information about each device found. This includes the device host name which is not retrieved during quick scans.

The data can be saved as a text document on the local computer, or printed on a connected printer. The Tools menu at the top lists programs to ping a selected IP address and to display all IP addresses found in a small window.

The ping command can be useful to check the response of a selected local IP address.

IP Seizer is a useful tool to quickly check for local IP addresses assigned to devices connected to a network. It’s portable nature makes it a handy tool for a troubleshooting DVD or USB stick.

The program is compatible with all recent 32-bit and 64-bit editions of the Microsoft Windows operating system. The latest version can be downloaded from the developer’s website.

It first needs to be mentioned that your computer may have multiple IP addresses. That’s the case for instance if you are currently connected to the Internet (which you may be since you are reading this text here) or if you have multiple network cards installed.

Each network card on your computer has a local IP address assigned to it. Plus, you get an IP address assigned to your computer whenever you connect to the Internet. The local IP address is only visible in the local network, for instance if a second computer in the network wants to communicate with yours. The Internet IP address on the other hand is often temporarily assigned, especially if you are on dial-up, DSL or cable.

Both local and Internet IP addresses look similar, each with four numbers separated by three dots. The core difference is that local IP addresses can only be accessed locally.

The easiest way to find out about your computer’s IP addresses is to use the ipconfig tool. Start the Windows command line with the hotkey Windows-r, typing cmd and the enter key.

Type ipconfig, or ipconfig /all for a detailed listing.

• IPv4 Address: This is the local IP address of the network card
• Default Gateway: This is the local IP of a router or other device that is used for connections (for instance to the Internet).

You cannot display the IP address that your computer has received from the ISP this way though. To find out my computer’s IP address I open http://www.ghacks.net/ip/ in a web browser of choice.

Your IP address will be shown to you along with the port and browser information. And that’s how you look up your computer’s IP address.

On a nicer note, it may be useful to know the location of a prospective client for business purposes so you may prepare a proposal significant to their demographic. This can be a benign and useful process as well as one to defend. The process is the same. You choose what to do with it. This gets technical, so prepare for some work.

Here is how to take the steps for Google, Outlook, and Yahoo.

Gmail

Log in to your Gmail account. Open the e-mail that for which you are seeking the origin.

Click the down arrow to the right of the reply ink and choose “Show original”.

Now this moves on to the technical part. Seek out the text lines that start with “Received From.” You can press Ctrl+F to search the phrase automatically. Note that there are many paths that the e-mail is received from. The true original location will be found furthest to the bottom of the text. It is advantageous to see all IP addresses involved. Here we find the original IP address and host name of the sender. Make sure you always select the last Received From entry in the listing.

Yahoo Mail

Open the email that you want to analyze. Scroll all the way down to the bottom until you see the toolbar at the bottom. Locate the Actions menu and click on it.

Select View Full Header to see all email header information.

Hotmail

Sign in to Hotmail and open the email. Locate the down arrow on the right side next to the Reply link. Click on the arrow and select View message source.

Locating the IP

The next step is to find the location of the IP address.

This is done by using a simple location lookup on the IP address. There are online programs that you can locate IP address information through, such as What Is My IP Address and these give broad map of the territory in which the IP address is located.

There are plenty of online services that allow you to look up IP address locations. When it comes to finding IP address locations for security purposes, it is important to find a reliable service. There are other services available. It is suggested that you use one, either free or with premium features at a small cost. This will make the discovery of the IP address location easy and minimize expenditure of time. It is a broad subject to go into when it comes to doing the search yourself. For practical purposes, third-party finders are affordable and accurate. Know where your e-mails are coming from. Mysteries mean risks. Otherwise, use the Ctrl+F option.

Sometimes it may be important to get detailed information about an IP address. Say you receive spam emails from a particular address all the time, or want to find out more about a person who stalks you, or are a webmaster who wants to find out who tries to brute force their server.

The IP address can provide you with valuable information in all cases. Please note that computer experts tend to use proxy servers or virtual private networks to cover their tracks. You would only see the last IP of the chain in this case, and not the IP of the device where it all started.

IPNetInfo is a lightweight portable software for Windows to look-up IP address information. It basically offers direct access to whois databases that you find on the Internet, for instance at a web host’s website.

The program displays a white text form on first startup that you can use to add IP addresses. It is possible to add IP addresses or hostnames manually, or paste them in from the Clipboard. Options are displayed at the bottom of the screen, of which some are already pre-selected.

The program will automatically resolve IP addresses and convert host names to IP addresses for instance. You can furthermore add a pause between look-ups which may be appropriate if you have added dozens, hundreds or even more IP addresses.

IPNetInfo will perform the selected operations. Each IP address is listed in a row in the main program interface. Core information, like the IP address and host name, country of origin, phone number or abuse email are displayed directly in each row. Detailed information about the selected row are displayed in the lower half of the program.

The information here resemble the whois look-ups on certain Internet sites, where information about a domain name or IP address can be obtained for free.

Reporting and exporting options are available. It is possible to create an HTML report of the look-ups, or save the information to text or xml files.

Another interesting option is located under Help > Show my current IP, which loads a web page where the current IP address of the computer is displayed. This is similar to our own IP address script where you get similar information.

You can download IPNetInfo from the developer website at Nirsoft. The program is fully compatible with 32-bit and 64-bit editions of the Windows operating system.

An IPv6 address has a few differences from IPv4. The first is that it is in hexadecimal instead of decimal. The second is that it is split up into larger segments and more of them. The third is that it uses colons (:) rather than periods (.) to divide these segments. In the end, one does not resemble the other. This is good because it prevents confusing the two.

Hexadecimal is better than decimal for a few reasons. For one, it takes up less space. The number “255″ is “FF” in hex; that is %50 smaller. Hexadecimal also relates more closely to binary. The number “1111″ is “15″ in decimal but “F” in hex. So “11111111″ is “FF” in hex, which is a much cleaner conversion than “255″ is. The downside is that humans typically think in decimal, so working with hex takes some getting used to.

IPv6 has a much larger address size. It has eight sections to it. IPv4 had half of that. The sections themselves are larger too: each one has four digits. IPv4 could only have three, and that only went to 255 tops. It should be obvious why this new address can afford all the room we have come to need. Hopeful it will for a long time. Here is a sample address.

FF00:00FF:0000:0000:0000:02f3:0000:0001

At this point, you may begin to see the down side to IPv6: it is long and hard to remember. To make them more human readable, there are a few conventions to short address when you have a lot of zeros present. First of all, you can skip leading zeros, so “0001″ becomes “1″ and “02f3″ becomes “2f3″ (IPv4 did this too). Second, groups of all zeros can be abbreviated to “::” (a double colon) once; you put nothing there. That makes “:0000:0000:0000:” reduce to “::” but “:0000:” cannot as it would be ambiguous. You can apply the first rule, making it “:0:” now. Putting all these rules into place gives us the following address.

FF00:FF::2f3:0:1

This address is about as long as an IPv4 number. Notice how the “00FF” shrank to “FF” and the “FF00″ did not. That was done intentionally to show the difference between leading and trailing zeros.

There is one more thing you really need to know if you are working with IPv6. The loop-back address, which was 127.0.0.1 in IPv4, is ::1 now. It works exactly the same way. You will have to use the ping6 command in Windows or Linux, so ping6 ::1 is what you would type into the command line. This will give many XP users an error as IPv6 may not be enabled on your computer. We have guides on how to enable IPv6 in XP, and how to assign IPv6 addresses in Linux.

Some other factoids about IPv6 are that it has is easier to route, more secure, and works better with mobile technology. There are changes to the way the packets of information are sent that makes it more efficient (e.g. better headers). It is more secure because it requires the use of IPSec, which is only optional in IPv4. IPv6 has an address recovery system, so when you change locations, it tries to keep the same address. These are are some of the that US government is switching over to it.

I should note that IPv6 has been found to have vulnerabilities. Malware tunneling is described in an article (note: a .pdf file) from the us-cert.gov site. It often has to do with how firewalls are configured. Different sources may give different opinions on how secure IPv6 is.

Wondering what happend to IPv5? It did exist. It was developed in the 1970′s to be used in audio and video streaming. It was called the Internet Stream Protocol. It did not get far past the experimental stage and was never adopted. Ideas from it helped to form IPv6.

The Ipconfig Command Basics

The ipconfig command gets its name from the acronym IP (Internet Protocol) and a shortened term for configure. Understanding this served as a mnemonic device for me when I was first learning networking. It is used to display and configure your connection to the Internet. This tutorial will focus on the display and what that means.

Deciphering the Information

To get to ipconfig, we have to get to the command line.

• Click Start, click Run, type in “cmd” & hit enter.
• Type in ipconfig & hit enter. (you can use ipconfig /all for detailed information)

You will get a screen that looks like this.

To find your router’s IP number, look next to “Default Gateway” (listed last). For a mnemonic, think of the router as your gateway to the Internet or another network. To find your computers’ IP number, look next to “IP Address”. Do not worry about the other information like the subnet mask.

In this case, the computer number is 192.168.1.4 while 192.168.1.1 is the router number. It is common for 192.168.1.1 or 192.168.0.1 to be the router’s IP address. There are a few reasons for this, which were covered in a previous article.

Ping Your Router (Default Gate)

We are using the ipconfig command so that we can get the IP number of the router. As discussed at the end of the last article on the ping command, we want to ping our router. If we can ping it, then it should be working properly.

To do this, type in ping and the router (default gateway) number as shown.

Some Possible Problems

Consider a case where the connection to the Internet seems down. If you cannot ping the router, or the ipconfig command says the default gateway is 0.0.0.0, then the problem may be in the router. The first thing to check is whether the router is on and everything is plugged in. The next thing to try would be to either restart the computer or to try and ping the router from another computer. From here, you may want to call your ISP’s help line and let them know what you have tried. An experienced user may restart the router; I have found that mine needs this from time to time. For a beginner, it is better to get some help. You will learn from the experience.

There is a possibility that your router may be failing. That has happened to me once before. Fortunately, a friend helped me troubleshoot the device, so stay in touch with networking pals. The culprit may likely have been heat from a lack of proper ventilation. Be sure your router has proper air flow. While they may run warm, if they are hot to the touch, it may be bad for the device (check your manual or consult your manufacturer).

ipconfig Command Line Options

Ipconfig has several command line options that you can utilize. You can display all of them with the command ipconfig /?. Here is a short selection of the most common uses.

• ipconfig /release – Releases all IPv4 addresses (requires DHCP)
• ipconfig /renew – Renews all IPv4 addresses (requires DHCP)
• ipconfig /flushdns – Flushes the DNS cache

Linux & Mac Use Ifconfig & Route -n

For those running Linux or are on a Mac, the commands to use are ifconfig and route -n. Is ifconfig identical to ipconfig? No. The ifconfig command will show you your computer’s IP number and other information. You just type in the command, ifconfig, into the terminal to find out information about how your computer connects to the Internet. To get your router’s IP number, you use the route command with a -n (netstat -r should work too). Both are shown in the screen shots. Make sure you use lowercase letter; the commands are case sensitive. (Side Note: Linux also has a iwconfig command for wireless specific tweaking (e.g. frequency).)

Just a note about the Mac ifconfig command. We are using it to view network settings, which is fine. In doing research for this article, I read that it is not advised to use this to change settings. From what I read, it works, but with possible complications.

Closing

We use ipconfig to find the router’s IP number. Once you have that, you can ping the router to test if it is responsive. The problem with the ping command is that, while it is fast, is doesn’t give you a lot of information. For that, we use the tracert command, which will be covered next.

It is not hard to secure your Wi-Fi connection. It takes changing a setting in the router and entering a password. Many, though, are not even aware that their connection is open, never mind that there are ways to secure it.

Cyber-attack and identity theft are only the most obvious dangers of having an open Wi-Fi connection. But there is another serious danger. If your connection is open and available to be stolen, the chances are good that someone is stealing it. The least malignant implication of this is that your neighbors will be watching Netflix on your connection, slowing you down and bringing a bandwidth cap that much closer.

But the real danger to you comes when your neighbors aren’t just watching Netflix. What if they’re doing something less reputable? What if they’re pirating music or engaging in illegal activities?

The RIAA and other organizations have been pushing courts to try people based on their IP addresses. There have been over 100000 law suits in the United States alone in the last year whose purpose was to obtain personal information on subscribers from ISPs in order to force the person to come to a settlement that ranges from hundreds to thousands of dollars. If your IP address has been tracked downloading music, etc, then you are obviously guilty, right? Well, not exactly. If your Wi-Fi connection is open, then anyone accessing the internet through it will have your IP address. Your neighbor could be the one who was tracked, or even someone driving down the street sniffing for open connections.

For this reason, people have been trying to get the justice system to understand for some time that an IP is not a valid way to determine whether or not a person has been engaging in piracy.

Finally, one judge seems to understand. Judge Herold Baker refused to allow a Canadian adult film site to subpoena ISPs for the personal information of subscribers. He said that an IP address does not equal a person. The fact that this case involves porn means that the judge felt he needed to handle it delicately. A wrongful conviction in a case like this could be even more damaging to a person than it otherwise would be.

Baker then went on to cite a recent mistaken child porn raid, where an IP address was turned into a name–but the named person hadn’t committed the crime. “The list of IP addresses attached to VPR’s complaint suggests, in at least some instances, a similar disconnect between IP subscriber and copyright infringer… The infringer might be the subscriber, someone in the subscriber’s household, a visitor with her laptop, a neighbor, or someone parked on the street at any given moment.”

This case is not a precedent setting case for the United States as a whole, per se. Still, it will be interesting to see if others follow Judge Baker’s reasoning. It’s refreshing to see that a judge seems to understand something about technology. It’s nice to see that the court isn’t totally ruled by the big corporations. I’m not in support of piracy, don’t get me wrong. But I am in support of decisions based on logic and proper information. Hopefully, the trend will spread…

What do you think of the judge’s decision? Do you support it? Do you think other judges will follow suit?

IPv6 offers a larger address space. The move from IPv4 to IPv6 is difficulty as it requires a coordinated effort from all parties including Internet users. Users with improperly configured computers may experience slowdowns, timeouts or other connectivity issues when the Internet moves to the IPv6 protocol.

Will you have troubles? You can find out if you run the IPv6 test. The test is an Open Source script that runs using JavaScript. Just visit the website http://test-ipv6.com and wait until the test has finished. The IPv6 test runs a series of tests including the browser’s IPv4 and IPv6 capabilities, IPv4 and IPv6 connectivity with and without DNS records and a test that checks if the ISP’s DNS server uses IPv6.

A click on test data reveals details about the tests.

Another click on Technical Info leads to a page that offers technical information about each test which may provide clues to troubleshoot the issue.

The most important test at this point in time for the majority of users is the dual stack test. There will be a transition period where websites and services can be reached via IPv4 or IPv6. The user’s computer now needs to pick one of the protocols and use it for the connection which means that devices that only support IPv4 at this time can still connect to the websites. Connectivity issues occur if this is broken.

Major services and websites will switch to IPv6 for a 24 hour period on World IPv6 day on June 8. Among them Google, Facebook and Yahoo. That’s where the dual stack DNS record support can be tested in a life environment.

And if the ping fails, other tools like tracert are there to provide deeper information on the connection issue.

Ping Info View is a Nirsoft application, which means it is a lightweight portable program for the Windows operating system. The free software can ping multiple host names and IP addresses in selected intervals.

The software displays the Ping Options window on first startup that contains a text area where the user can add host names and IP addresses to ping. Available as well are configuration options including the ping timeout in ms, the interval in which pings are fired of from the local PC and whether the host names and IPs should be remembered by the program.

Once the configuration has been finalized the data is transferred to the main interface of the application where all servers are pinged automatically.

The portable software displays the host name and IP address, the reply IP address, the number of successful and failed counts and the failed percentage. It furthermore indicates non responding host names or IP addresses with a red icon, and responding servers with a green icon.

The initial configuration window is available under File > Ping Options so that new servers can be added to the list, or old ones removed. It supports the import of a server list from a text document which can be handy for users who need to ping many servers that are stored in a text document.

Ping Info View offers to create HTML reports and save selected information in text files. The program is available for download at the Nirsoft homepage. It should work fine with most Windows operating systems. Ping Info View was tested on a Windows 7 64-bit Pro system.

Manually changing a network adapter’s IP address, and other network related information may be an option if done irregularly, but a software to automate most of the process could save a lot of time.

TCP Profiles Manager is a basic software for this purpose. It supports the creation of multiple network profiles, but limits the parameters that may be changed to TCP/IP and DNS settings.

tcp profiles manager

The program on startup displays a list of available profiles, and options to create, delete, edit and activate profiles in the left sidebar. First time users should make sure that English is the selected language of the program. As a side note, the installation is only available in French, the software itself in English and French.

A new network profile requires the selection of a name, icon, network interface, either manual or automatic IP address settings, and a manual or automatic selection of DNS servers.

internet protocol

TCP Profiles Manager lacks some of the features that previously reviewed applications offer. Network Settings Manager for instance offers options to configure default printers, network drives, WINS or scripts for each network profile.

Even the similar Network Profile Switcher supports plugins to change settings like the Internet Explorer proxy automatically for each network profile.

Still, Windows users who are looking for a program that changes IP and DNS related network settings automatically, may take a look at TCP Profiles Switcher. Advanced users, and users who require more functionality may be better of with NetSetMan.

TCP Profiles Manager is compatible with 32-bit and 64-bit editions of the Windows operating system. It has been tested on a Windows 7 Pro 64-bit system.

The tool basically allows the user to configure multiple IP profiles that can be activated with the click of the mouse. IP Switcher is a portable software program that displays a two-tiered interface on startup.

The software program displays all connected network adapters at the top and the configured IP configurations at the bottom.

Network adapters are displayed with their name, description, status and current IPv4 and IPv6 IP address.

A new IP address, which actually consists of more than just the IP can be easily added for the selected adapter. It is possible to add a IPv4, IPv6 or IE Proxy IP address easily.

The configuration includes the IP address, subnet mask, default gateway, interface metric and DNS server for that configuration.

The different IP addresses can then be accessed from the Windows system tray. Hovering the mouse over the icon displays the current IP information.

A right-click on the icon can then be used to set an IP address for the selected network adapter. IP Switcher is a handy tool for users who have to work in different network environments that force them to change IP related settings regularly. The 65K program can be downloaded from the developer’s website. It is compatible with both 32-bit and 64-bit editions of the Microsoft Windows operating system and requires the Microsoft .net Framework 2.0.

In this article I will show you how to find out various networking information on your Linux system. All of these tasks can be handled by any skill level of user, so don’t think you have to be an ubergeek, hacker-type in order to gain this information.

IP Address

Figure 1

Let’s start off with the IP Address. Of course, before you do anything, you need to open up a terminal window. Once you have that open you can then issue the necessary command. The command for finding your IP Address is ifconfig. When you issue this command you will receive information for every network connection you have available. Most likely you will see information for both the loopback (lo) and your wired network connection (eth0). If you have a wireless connection that will be listed, most likely, as wlan0. The reported information will look like that shown in Figure 1. As you can see, you not only get the IP Address, but the Broadcast address, the Subnet Mask, and the IPv6 Address.

Hostname

From that same command line, if you enter the command hostname you will see the actual hostname of your machine. In the case of my test machine, I see Ubuntu-desktop.  For more information on using this command, take a look at my article “Set your hostname in Linux“.

DNS Address(es)

There is no actual command to see your DNS addresses. You don’t really need one. All you need to do is examine the /etc/resolv.conf file with the command less /etc/resolv.conf, at whichpoint you will see something like:

nameserver 208.67.222.222

nameserver 208.67.220.220

Gateway address

Figure 2

Now let’s find out what the Gateway address is. The command used for this is the netstat command. This command does quite a bit more than just discover your gateway. What the netstat command does is print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. But to find the gateway address you would issue the command netstat -nr and you will see something like that shown in Figure 2. You can probably guess it, but the Gateway address is 192.168.1.1. The flags you used in that command are n (for numeric addresses) and r (for route).

Of course the netstat command can do much more than that (we’ll cover that in another article).

Final thoughts

Yes, there are a lot of tools that can be used in Linux. It all depends upon how you want to get your information. In both the GNOME and KDE desktops there are outstanding GUI tools you can use for all of this. But knowing the command line route makes you much more versatile.

How to look up the private IP address

The easiest option to look up the private IP address on PCs running the Microsoft Windows operating system is to press Win-R, type cmd and hit enter. This opens a command line prompt. Entering the command ipconfig will display the private IP address of every network adapter of the computer.

How to look up your public IP address

The public IP address is usually assigned to the computer by an Internet Service Provider (ISP). They can be divided into static and dynamic IPs with dynamic IPs assigned to home owners usually.

The easiest way to lookup the public IP address is to use a script on a website that displays it. You can for instance point your web browser to http://ghacks.net/ip/ to look it up.

Computer users without a router, e.g. those on a dialup connection, can issue a command to find out their public IP address much like they can find out their private IP.

They need to enter the command line again in Windows (press Win-R, type cmd and hit enter). The command netstat -n will display the active connections. The IP address is shown in the left column of the output.

Users with a router can find out the public IP address by loading the router’s administration interface. Most routers display the public IP address in that interface.

Do you have another tip to display the public or private IP address easily? Let us know in the comments.

Inexperienced computer users on the other hand might want to take a look at the Simple Static IP networking tool which allows them to set a static IP address with a few clicks of the mouse button.

A user who wants to set a static IP address needs to select the network adapter from the pull down menu on top of the application’s interface. Simple Static IP will then display the current settings of the network adapter including the assigned IP address, subnet, gateway and DNS server.

A click on Enable Static IP will configure a static IP address for the selected network adapter. It is possible to keep the DNS settings or use the router or the Open DNS servers as the dns server for the network adapter. It is also possible to randomize the static IP address by clicking on the Randomize New IP button in the interface.

Simple Static IP is compatible with the following Microsoft operating systems: Windows 2000, XP, 2003, Vista, 2008.

The IP address. Your gateway to the internet. That little set of numbers that guarantees you can log on and check mail, watch videos, etc. This is something I only used to bother about when my internet connection stopped working and I needed to check if there was a problem from my end.

All this while, my ISP had assigned me a static IP address. Then, a few days ago, someone from the ISP called me up asking me to change some settings. Turns out they are now assigning dynamic IPs to their users.

While my internet experience hasn’t really changed significantly, I got curious about the merits and demerits of both types of IP addresses. From what I’ve gleaned so far, the type of IP address doesn’t matter for the average home user. However, if you run some kind of server like Web, FTP, Email etc. then you definitely need a static IP address. I’m still not sure which one is better though so I’d like to get ghacks readers’ opinions on the subject.

What kind of IP address do you use? Have you ever had problems and had to switch? What advantages and disadvantages have you noticed with dynamic and static IP addresses? Let me know in the comments.