How would you communicate with a device when you don’t have the IP?
You might be in a situation where you don’t have the IP address of a device in a local network, but all you have is records of the MAC or hardware address.
A server accessible via SSH on a public IP address; The IP address of the remote server; The username and password of a user on the server; A Mac OS computer; Connecting to a Server via SSH in Terminal Step 1: Open Terminal. In Finder, open the Applications folder and double click on the Utilities folder. How to Find MAC Address of a Smartphone – Android, Windows and iOS devices: MAC address is a unique identifier or a unique physical address of a device. Like your home address, the MAC address is an identity of your device on the internet. No two devices in the world would ever have identical MAC addresses. The MAC address is manufactured into each network card like Ethernet card or Wi-Fi card and there cannot be changed, so every device has a MAC address. The newly launched Amazon echo devices are also have a MAC address like every devices so you need to find it at some time, it is very important to know about how to find MAC address for Amazon.
Or your computer is unable to display its IP due to various reasons, and you are getting a “No Valid IP Address” error.
Finding the IP from a known MAC address should be the task of a ReverseARP application, the counterpart of ARP.
But RARP is an obsolete protocol with many disadvantages, so it was quickly replaced by other protocols like BOOTP and DHCP, which deal directly with IP addresses.
In this article, we’ll show you how to find IPs and device vendors using MAC addresses with different methods for free.
Understanding ARP
ARP (Address Resolution Protocol) is the protocol in charge of finding MAC addresses with IPs in local network segments.
It operates with frames on the data link layer.
As you might already know, devices in the data link layer depend on MAC addresses for their communication.
Their frames encapsulate packets that contain IP address information.
A device must know the destination MAC address to communicate locally through media types like Ethernet or Wifi, in layer 2 of the OSI model.
Understanding how ARP works can help you find IPs and MAC addresses quickly.
The following message flow diagram can help you understand the concept:
- The local computer sends a ping (ICMP echo request) to a destination IP address (remote computer) within the same segment. Unfortunately, the local computer does not know the MAC address… it only knows the IP address.
- The destination hardware address is unknown, so the ICMP echo request is put on hold. The local computer only knows its source/destination IP and its source MAC addresses. ARP uses two types of messages, ARP Request and Reply.
The local computer sends an ARP REQUEST message to find the owner of the IP address in question.
This message is sent to all devices within the same segment or LAN through a broadcast MAC (FF:FF:FF:FF:FF:FF) as the destination.
- Because the remote computer is part of the same network segment, it receives the broadcast message sent by the local computer. All other computers in the LAN also receive the broadcast but they know that the destination IP is not theirs, so they discard the packet. Only the remote computer with destination IP, responds to the ARP REQUEST with an ARP REPLY, which contains the target MAC address.
- The local computer receives the ARP REPLY with the MAC address. It then resumes the ICMP echo request, and finally, the remote computer responds with an ICMP echo reply.
Finding IPs with ARP
You can use ARP to obtain an IP from a known MAC address.
But first, it is important to update your local ARP table in order to get information from all devices in the network.
Send a ping (ICMP echo reply) to the entire LAN, to get all the MAC entries on the table.
To ping the entire LAN, you can send a broadcast to your network.
Open the Command Prompt in Windows or terminal in macOS and type.
ping 192.168.0.255
My subnet is 192.168.0.0/24 (mask of 255.255.255.0), so the broadcast address is 192.168.0.255 which can be calculated or found with a “Print Route” command in Windows or a “netstat -nr” in macOS. Or can also be obtained with a subnet calculator that you can download for free.
For Windows:
Step 1.
- Open the CMD (Command Prompt)
- Go to the “Start” menu and select “Run” or press (Windows key + R) to open the Run application
- In the “Open” textbox type “cmd” and press “Ok”.
This will open the command-line interface in Windows.
Step 2.
- Enter the “arp” command.
- The arp command without any additional arguments will give you a list of options that you can use.
Step 3.
- Use the arp with additional arguments to find the IP within the same network segment.
- With the command “arp -a” you can see the ARP table and its entries recently populated by your computer with the broadcast ping.
Step 4.
- Reading the output.
- The information displayed in the arp-a is basically the ARP table on your computer.
- It shows a list with IP addresses, their corresponding physical address (or MAC), and the type of allocation (dynamic or static).
Let’s say you have the MAC address 60-30-d4-76-b8-c8 (which is a macOS device) and you want to know the IP.
From the results shown above, you can map the MAC address to the IP address in the same line.
The IP Address is 192.168.0.102 (which is in the same network segment) belongs to 60-30-d4-76-b8-c8.
You can forget about those 224.0.0.x and 239.0.0.x addresses, as they are multicast IPs.
For macOS:
Step 1:
- Open the Terminal App. go to Applications > Utilities > Terminal or Launchpad > Other > Terminal.
Step 2:
- Enter the “arp” command with an “-a” flag.
- Once you enter the command “arp -a” you’ll receive a list with all ARP entries to the ARP Table in your computer.
- The output will show a line with the IP address followed by the MAC address, the interface, and the allocation type (dynamic/static).
Finding IPs with the DHCP Server
The Dynamic Host Configuration Protocol (DHCP) is the network protocol used by TCP/IP to dynamically allocate IP addresses and other characteristics to devices in a network.
The DHCP works with a client/server mode.
The DHCP server is the device in charge of assigning IP addresses in a network, and the client is usually your computer.
For home networks or LANs, the DHCP Server is typically a router or gateway.
If you have access to the DHCP Server, you can view all relationships with IPs, MACs, interfaces, name of the device, and lease time in your LAN.
Step 1.
How To Know Passphrase For Mac Address Password
- Log into the DHCP Server. In this example, the DHCP server is the home gateway.
- If you don’t know the IP address of your DHCP Server/ Gateway, you can run an ipconfig (in Windows) or ifconfig (in macOS/Linux).
- This particular DHCP Server/Gateway has a web interface.
Step 2.
- Enter the IP address on the search bar of the web browser, and input the right credentials.
Step 3.
- Find the DHCP Clients List.
- In this TP-Link router, the DHCP Server functionality comes as an additional feature.
- Go to DHCP > DHCP Clients List. From this list, you can see the mapping between MAC addresses and their assigned IPs.
Using Sniffers
If you couldn’t find the IP in the ARP list or unfortunately don’t have access to the DHCP Server, as a last resort, you can use a sniffer.
Packet sniffers or network analyzers like Nmap (or Zenmap which is the GUI version) are designed for network security.
They can help identify attacks and vulnerabilities in the network.
With Nmap, you can actively scan your entire network and find IPs, ports, protocols, MACs, etc.
If you are trying to find the IP from a known MAC with a sniffer like Nmap, look for the MAC address within the scan results.
How to find the Device and IP with a Sniffer?
How To Know Passphrase For Mac Address Computer
Step 1.
- Keep records of your network IP address information.
- In this case, my network IP is 192.168.0.0/24. If you don’t know it, a quick “ipconfig” in Windows cmd or an “ifconfig” in macOS or Linux terminal can show you the local IP and mask.
- If you can’t subnet, Download this Free Subnet Calculator tool or go online to a subnet calculator and find your network IP.
Step 2.
- Download and open Nmap.
- Download Nmap from this official link https://nmap.org/download.html and follow its straightforward installation process.
Step 3.
- Open Nmap (or Zenmap) and use the command “sudo nmap -sn (network IP)” to scan the entire network (without port scan).
- The command will list machines that respond to the Ping and will include their MAC address along with the vendor.
- Don’t forget the “sudo” command.
- Without it, you will not see MAC addresses.
Finding out the device vendor from a MAC address
Ok, so now you were able to find out the IP address using “arp -a” command or through the DHCP Server.
But what if you want to know more details about that particular device?
What vendor is it?
Your network segment or LAN might be full of different devices, from computers, firewalls, routers, mobiles, printers, TVs, etc.
And MAC addresses contain key information for knowing more details about each network device.
First, it is essential to understand the format of the MAC address.
Traditional MAC addresses are 48 bits represented in 12-digit hexadecimal numbers (or six octets).
The first half of the six octets represent the Organizational Unique Identifier (OUI) and the other half is the Network Interface Controller (NIC) which is unique for every device in the world.
There is not much we can do about the NIC, other than communicating with it.
But the OUI can give us useful information about the vendor if you didn’t use Nmap, which can also give you the hardware vendor.
A free online OUI lookup tool like Wireshark OUI Lookup can help you with this.
Just enter the MAC address on the OUI search, and the tool will look at the first three octets and correlate with its manufacturing database.
Final Words
Although the RARP (the counterpart of ARP) was specifically designed to find IPs from MAC addresses, it was quickly discontinued because it had many drawbacks.
RARP was quickly replaced by DHCP and BOOTP.
But ARP is still one of the core functions of the IP layer in the TCP/IP protocol stack.
It finds MAC addresses from known IPs, which is most common in today’s communications.
ARP works under the hood to keep a frequently used list of MACs and IPs.
But you can also use it to see the current mappings with the command arp -a.
Aside from ARP, you can also use DHCP to view IP information. DHCP Servers are usually in charge of IP assignments.
If you have access to the DHCP server, go into the DHCP Client list and identify the IP with the MAC address.
Finally, you can use a network sniffer like Nmap, scan your entire network, and find IPs, and MACs.
If you only want to know the vendor, an online OUI lookup like Wireshark can help you find it quickly.
Mediacom routers are popular among small business and individuals. The company Mediacom operates in 22 states of US. The company also provides routers to their customers. The function of router is that one can easily manage their routers using Mediacom Home Network Manager. With Mediacom Home network manager, internet service can be shared among all the devices connected to the internet. But the issue users face in Mediacom router login as it requires the credentials and address to get even to default gateway page.
Features of Mediacom Routers:
Mediacom Home Network System allows you to manage networks. They provide easy to use tools that will assist customers to:
- Setting up and administering the network;
- Manage or change your Wi-Fi settings;
- Setting Port Forwarding (set up port forwarding for the most popular multiplayer games, media devices, and messaging applications).
Accessing Mediacom Router Login:
Mediacom router is managed totally by Mediacom Cable Company, so you have to use their home network software to get an access to your router. You can change the name of Wi-Fi network or set up a new password or set up port forwarding for devices, change DHCP server settings, set up a firewall and configure other common router settings for your home network. After signing in with Mediacom username and password you can reset your password or can change Wi-Fi settings by clicking the “Wi-Fi” option in the panel or by clicking “Port Forwards” you can set up port forwarding.
How to Access Mediacom router admin login panel
Step 1: To access the Mediacom Home Network Manager
Go to address: homewifi.mediacomcable.com or you can simply copy paste this in your search bar of the browser.
Step 2. This will connect to the administration panel of your router where you need to enter your Mediacom ID in the username and the passphrase
- Username: Mediacom ID
- Passphrase: Default password.
Note: in case you have forgotten your password, you can click ‘Forgot your passphrase” and enter the mail id used while setting the Mediacom account. Once verified, you will receive new passphrase to login.
Sometimes default combination of following credentials can work:
- Username: admin
- Password: admin
Step 3: Once you enter the credentials, you will be directed to admin panel where you can
- Change SSID
- Change Default Username and Password
- Change DHCP Settings
- Setup Firewall
- Configure the Router for the home network
Step 4: For users who want to change the default username and password of Mediacom router login.
- Go to https://homewifi.mediacomcable.com/prime-home/control-panel/login/ or visit 192.168.100.1 or 192.168.0.1
- Enter your password
- Select the login option available on the control panel page
- You will find “My Wireless Network” to the left side
- Select the Wi-Fi option, upon clicking you will see SSID (Service Set Identifier) and Passphrase option on the right.
- Now, you can change the network name also called SSID and passphrase as per your ease
- Once done, select save and your changes will be updated
How to reset Mediacom router ?
Experiencing issues with your Mediacom Router? Router not working/not connected to network. In this case you have to perform reset.
A soft reset will reboot the router but router setting will not get affected. Soft reset can be performed by unplugging the power cable for five minutes. Plug it back and wait for router to reboot. The process will take about 5-10 mins. Check if router is working by surfing the internet in your device.
Also Read :
Hard reset is also an option but it will change your Wi-Fi settings. To perform hard reset first you have remove the co-axial cable and then press the reset button on the back of router for at least 30 seconds. The lights of the router will start flashing and then wait for the router to reset completely.
Connecting Devices to Mediacom Router Login
Other devices can be connected to Mediacom routers the same way you connect to other networks.
On Windows:
- Click the “Network” icon in the bottom right corner
- Then select the Mediacom Wi-Fi network. Click the “Connect” button and type in the Wi-Fi network password.
- Hit the “Next” button to connect to the Mediacom router.
On Mac:
- Click the “Network” icon in the top right corner
- Select your Mediacom network.
- Type in your Wi-Fi password and click “Join” to connect.
Conclusion:
Mediacom cables company offer broadband services and the routers Mediacom provides are managed and configured by home networks. Only thing you need to access your router settings is username and password.