Finding Lost IP Address of Device on Network Guaranteed!

I bet this has happened to every technician at least once. You get handed an IP camera to install and you drive all the way to site only to find that the IP camera isn't showing up on your search tools. OK, no worries. You Google the default IP address, give it a ping... and squat. It's lost in the (nearly) endless void of IP addresses.

Don't worry, it happens. This guide will walk you through troubleshooting connectivity issues and lost IP devices.

 

Back to basics.

I know it's simple but if you haven't already, Google search the default IP address. Like I said, simple. But you'll probably find that most issues won't be this easy to fix.

If the device is DHCP (meaning the IP address is allocated by the router) you can sometimes find a list of devices connected to a network in the routers web interface. To find the IP address of your router, you can use Command Prompt and type 'ipconfig'. The command will then output a list of all network connections and their associated IP settings. Your routers IP address will be listed as the 'default gateway'.

Finding your default gateway

Once you've got your router's IP, visit the web interface by putting the IP address in your browser. You'll probably be asked for a username and password which are usually kept default (AND IF IT IS, CHANGE IT) and most probably printed on a sticket on the bottom of the router. Every router will be different but you want to look for something along the lines of 'attached devices'. Here's an example from my Telstra Smart Business Modem.

Router configuration page


The MAC address of the device can be used to identify which IP belongs to your camera. This is usually printed on the bottom of the device.

There's a good chance the device might just be blocking ping attempts so also check the connectivity using a different protocol such as trying to view the web interface (in your browser) or pulling a stream via RTSP.

 

Still nothing? Don't give up!

If you don't find anything in the browser, the device probably has a static IP address which is not inside the routers network range.

You can try searching for Address Resolution Protocol (ARP) messages on your computer. To do this, open command prompt again and type 'arp -a'. The command will output a list of devices which have shared ARP requests with your computer.

ARP tool Windows

Then search the physical address column for an entry matching the MAC address of your device.

 

Time to bring out the big guns.

Wireshark Logo

This last method is guaranteed to work 100% of the time (unless your device is dead). Wireshark is a network capture tool which lets you view all network activity on any network your device is connected to.

Now, we could use Wireshark on the entire network but if you don't know what your doing, you will have trouble searching through all the packets to find what your after. To make things a little easier, its best to setup the device on its own network (e.g. connected the device directly in to your laptops ethernet port).

You can download Wireshark from their website.

Once you have installed Wireshark (and Npcap which should automatically install), open it up and you should see a list of network adapters connected to your computer along with a graph showing the network activity of each.

Wireshark network interfaces

If you have multiple adapters, disconnect from all other networks and wait till the graphs flatten out. The one which has a small amount of network activity should be the one your device is connected to.

Once you've found the correct adapter, double click it to start capturing packets. It might look a little complicated but I assure you, it's dead simple for what we are doing.

Since you only have 2 devices on your network (your computer and the device we lost), any activity in the top table that gives us an IP address will do. In particular, your likely to see a lot of ARP requests (highlighted yellow).

Wireshark results table


The 'Info' column breaks down the packet in to a nice, human readable format. For example you might see:
Who has 192.168.1.1? Tell 192.168.1.32

So now we know that a device at 192.168.1.32 is looking for a device at 192.168.1.32. Most likely, the device at 192.168.1.32 is our lost device (YAY!) and its looking for the configured default gateway at 192.168.1.1.

If this isn't the right IP address, keep looking in the table and try and find other hosts. You should also try different network adapters if you are unsure which is correct.

 

Great! Now we have the IP... but how do we connect to it?

Now you can change your network adapter in to the correct network range in order to communicate with the device. To do this, right click on the network icon in your taskbar and click 'Open Network & Internet settings'.
Network settings Windows

Then choose 'Change adapter options' under Advanced settings.
Windows Network Settings

Right click on the adapter you will use to connect to the device (ethernet or wifi) and select Properties.
Windows Network Settings

Select 'Internet Protocol Version 4' then click the Properties button.
Windows Network Settings

Enter an IP address in the same network as our lost device. For example, if the device IP is 192.168.1.32 we can set our IP address as 192.168.1.99. If your lost device IP is 10.13.21.60 you could choose 10.13.21.3. As long as the first 3 sections (divided by .) are the same, you will be in the same network range. Set the subnet mask as 255.255.255.0 and leave everything else blank.
Windows Network Settings

Click 'OK' and your good to go! You'll probably want to change the IP address of the device back to DHCP or a static address in the same range as your router so you can use your device on your network.

Once your done, make sure you change the network adapter back to 'Obtain IP Address Automatically' so you can reconnect to your network via DHCP.

If your having trouble with an item you purchased from Ripple Security, give us a call, send us an email or shoot us a message on Facebook. Our friendly technical support team are always happy to help.