Address Resolution Protocol & Display ARP Cache On Computer

Address Resolution Protocol(ARP) finds Physical address(MAC Address) of a network host from IP address of that host. To communicate between two devices, source device must know the IP address and MAC address of the destination device. If the destination device does not have MAC address of the destination device, it sends ARP broadcast to find the MAC address of the network host belongs to the IP address. The device having the IP address(destination device) will respond to the source device with its MAC address. Source device will update ARP cache with the newly find MAC address of the destination device. ARP cache stores MAC address of the other network devices for the future use and periodically undergo flushing to avoid obsolete entries.

How to Display ARP cache On A Computer

To view the MAC address entries stored in ARP(Address Resolution Protocol) cache on your computer, follow the steps below.
  1. Start Command Prompt

  2. Type arp -a to display current ARP entries on your computer
    Table of ARP Cache on My Computer

    PS: arp -g can also be used to display ARP cache on a computer.

On the table, you can find the Physical address of destination devices with IP addresses. Dynamic APR entries are address automatically but the static types are added manually. Static ARP entries remain on ARP cache on your computer until you reboot the system.

ARP Commands
  1. arp -v -This APR command shows current ARP entries in verbose mode.

  2. arp -d - This ARP command can be used to delete a particular ARP entry specified by IP address from ARP cache

  3. arp -s can be used to add a host to APR cache with MAC address and IP address. ARP entries added to ARP cache using this command is permanent and remains until you reboot your computer.

Other Popular Network Protocols

  1. Interior Gateway Routing Protocol (IGRP)

  2. Routing Information Protocol (RIP)

  3. Internet Control Message Protocol (ICMP)

  4. Dynamic Host Configuration Protocol (DHCP)

How to Add a Static Entry in ARP Cache

To add a static entry in ARP cache you can use the command arp -s. The format is provided below.

arp -s 224.0.0.22 01-00-5e-00-00-16

CoreNetworkZ- Network Portal

Getting Device Manager Error Code 10

If any device connected to your computer is not working properly, first step is to check its status in Device Manager (DM). This tutorial explains device manager error code 10 and the solution to fix it. It tells the device cannot be detected by the computer. Error code 10 comes with following message: This device is either not present, not working properly, or does not have all the drivers installed. (Code 10). Now let us check the normal troubleshooting steps to resolve it.

Standard Procedure to Fix Device Manager Error Code 10
  1. Check Connectivity

    If the hardware not connected properly, you will get this popup. So make sure the unit is connected properly.

  2. Reseat the unit

    It is an extension of first step. You just disconnect the device and reconnect it. Check if the issue persists. This procedure is easy for USB devices because they offer plug and play support. For example if you are using USB wireless adapter to connect your PC to a WiFi network and having the same problem, you may disconnect the adapter from the USB port of your PC and reconnect. After reconnecting the adapter, check for the issue.

  3. Update Driver

    In most cases, outdated driver causes the altert This device is either not present, not working properly, or does not have all the drivers installed. ( 10). Update the current driver installed with latest driver available. You can do it from Device Manager by selecting the hardware which shows issues. To access DM on your computer, follow the instructions provided in the link below.
    How to Access DM

If you are not sure, how to update outdated driver, follow the instructions provided in the link below. You can follow the same method for every hardware units.
How to Update Driver

Just like this issue, another common error is code 1. To learn the reasons and solution to fix that error, visit the link below.
DM Error Code 1

Rarely you may see troubles on your laptop if an adapter is manually disabled. There is a different procedure to handle this situation. To read more about it, visit the link below.
How to Enable WiFi Adapter

Technology Portal

This Device is Not Configured Correctly. (Code 1)

If your computer is unable to configure a device, device manager (DM) will show you error code 1. The complete error code 1 is This device is not configured correctly. (Code 1) To update the drivers for this device, click Update Driver. If that doesn't work, see your hardware documentation for more information. This DM alert is self explanatory. By reading the message itself one can understand the real reason to get this alert. The message also suggests the most effective solution for device manager error code 1.

Solve Error Code 1
  1. Update Driver

    As the warning suggests, the first step to solve error code 1 is to update the driver. To learn how to update driver installed on your PC, click the link below.
    How to update Driver

  2. Remove the Device

    If the updated unit failed to fix the problem, you may want to delete it from Device Manager (DM). After deleting the hardware, you can reconnect it using Add New Hardware Wizard from Control Panel.

If you are still getting error code 1 even after following the both steps, it is the time to check the hardware documentation of the device. Certain devices will not work properly with certain versions of Windows. So you must double check whether the unit you are trying to configure on your computer supports the Operating system and other system settings. If you have migrated from Vista to Windows 8 or 7 recently, there is a chance to see this popup due to the compatibility issues. The hardware unit may not be compatible with latest Operating Systems. Though Windows 8 and 7 has the feature to run a program designed for older versions, rarely incompatible drivers cause issues and warning. You can use "Run this program in compatibility mode for" feature to run the program or hardware unit for current Microsoft OS version.

Further Readings
  1. DM Error PopUp 10

  2. Download Best Free LAN Messenger Tools

  3. How to Download and Create Log Files For IP Messenger Installed

  4. How to Perform Reverse Image Search On Your Computer

Technology Portal

Interior Gateway Routing Protocol (IGRP)

Interior Gateway Routing Protocol (IGRP)
____________________________________

IGRP is an interior gateway protocol

invented by cisco to replace the RIP.

It is a distance-vector routing protocol

used by routers to exchange routing data

within an autonomous system.



Important points
_______________
1. IGRP supports multiple metrics for each

route, including bandwidth, delay, load,

MTU, and reliability

2.The maximum hop count of IGRP-routed

packets is 255 (default 100).



disadvantage
__________________
1. IGRP is considered a classful routing

protocol.


New CCNA Topics

Routing Information Protocol (RIP)

Routing Information Protocol (RIP) - CCNA Tutorials




The Routing Information Protocol (RIP) is a dynamic routing protocol.It is inside the network to create a routing table
which helps routers to understand the layout of the network with changes in network connections. RIP is an interior gateway protocol (IGP) using the distance-vector routing algorithm.

Working of Routing Information Protocol

RIP is a distance-vector routing protocol. It uses hop count as the routing metric. 15 is the maximum number of hops allowed in RIP. RIP sends routing-update messages at regular intervals and when the network topology changes.The normal RIP updation time is 30 seconds while the hold down time is 180 seconds. RIP is based on UDP and working on the Transport layer. Routing by RIP is also called routing by rumor.



RIP Stability Features

RIP implements following mechanisms to maintain the stability. They are:

1. Split horizon
2. Route poisoning
3. Holddown mechanisms


Different versions of RIP

The major versions of Routing Information Protocols are:

1. RIP version 1

2. RIP version 2

3. RIPng

RIP version 1is the basic RIP which doesn't support VLSM. This drawback is fixed on the RIP version 2 where it support Variable Length Subnet Mask (VLSM).RIP version 2 is using multicast where RIP version 1 is using broadcast to send routing updates.RIP version 2 multicasts routing updates to the address 224.0.0.9.RIPng is specially defined for IP version 6.

Suggested Readings


1. Interior Gateway Routing Protocol (IGRP)

2. Address Resolution Protocol (ARP)

3. Internet Control Message Protocol (ICMP)

4. Dynamic Host Configuration Protocol (DHCP)


New CCNA Topics