Virtual Router Redundancy Protocol (VRRP)

Virtual Router Redundancy Protocol (VRRP) introduces the concept of virtual router to improve the redundancy of default gateway of hosts. According to VRRP, virtual router (VR) is not just a physical router but includes the master and backup routers. Backup router will take place the position of master  if the master becomes unavailable. So the default gateway of a host is configured as VR instead of single physical router. However, at a time only one master is acting as the default gateway and master informs the backup routers its current status all the time.


Virtual Router Redundancy Protocol is open source protocol which is very similar to Cisco's proprietary protocol Hot Standby Router Protocol. However, both protocols are not compatible despite of their similarities.

VRRP Configurations Tips
  1. Default gateway of hosts is configured to VR

  2. A group of physical routers comes under VR but only single master works at a time

  3. Master informs backup routers its current status

  4. When master fails, one backup router assumes the role of master

  5. Concept of Virtual router by Virtual Router Redundancy Protocol, improves the redundancy

  6. MAC address of VR must be configured as 00-00-5E-00-01-XX

  7. IP address used for multicast is

Other Routing Protocols
  1. Internet Control Message (ICMP)

  2. Internet Group Management (IGMP)

  3. Generic Attribute Registration (GARP)

  4. Remote Procedure Call (RPC)

No:Recent Tutorials
1 Fiber Distributed Data Interface (FDDI)
2Network Layer
3 Control Packets Traffic Using Access Control List
Configure Generic Attribute Registration Protocol (GARP) with GVRP
Address Resolution Protocol & Display ARP Cache On Computer
Interior Gateway Routing Protocol (IGRP)
Routing Information Protocol (RIP)
Internet Control Message Protocol (ICMP)
Delete Saved Preferred Wireless Network Profiles On Windows

How to Setup DSL Connection On Fedora Linux

If you are using Fedora Linux on your computer, it is very simple to connect a DSL Internet connection. This tutorial tells the procedure to add a DSL broadband connection to a computer having Fedora Linux. It is a GUI method and we do not need to go to terminal to complete the procedure. Steps are provided below.

Configure DSL On Computer Having Fedora Linux

  1. Go to desktop>Administration> Network

    You can also reach network by typing the command system-config-network.

  2. On Network Configuration window, follow the steps below.

    • Click on toolbar and select new
    • It will open a new window Add new Device Type.
    • Choose DSL connection and click forward
    •  Enter the ISP details including user name and password.

  3. Check Internet Connection

    To check Internet connection on Fedora Linux, go to Network Configuration window.

    •   Select new connection window
    • Click on activate
    • Type ping

    If we receive reply, connection is working fine.

  4. Disconnect Internet From Fedora Linux

    To disconnect DSL connection, click the Deactivate button from the network configuration window.

Suggested Topics

  1. Configure Broadband On Ubuntu Linux

  2. Resolve Getting 169.254.X.X (APIPA)Automatic Private IP Address

  3. How to Use Ping Utility

No: Recent Posts
Configure Broadband On Ubuntu Linux
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Ping Gives Hardware Error
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Connection Issues With Tata Photon
PING: Transmit failed. General Failure
Ping Request Could not Find Host
Error 628: The Connection was Terminated by the Remote computer

How to Configure Broadband On Ubuntu Linux-- Simple Guide

It is not difficult to configure broadband connection on a computer running Ubuntu Linus. This guide tells commands and procedure to configure DSL connection on Ubuntu step by steps.Make sure you have the Ubuntu setup disc. Make sure your computer is connected to modem using an Ethernet cable.

Procedure to Setup Broadband On Ubuntu Computer

  1. Connect your modem/router to your computer using a LAN cable

    In Linux, Network cards(NIC) are named as eth0, eth1... and the naming depends on the order of detection of Network cards. If you have only one LAN card (Network card), it will be listed as eth0. If you have another, it will be eth1, and so on. If you have multiple cards, you need to find out which one is really eth0 and which one is really eth1 etc. (in Debian and Ubuntu, the configuration script will automatically detect the card which is connected to ADSL modem/router).

  2. Install pppoeconf package

    In Debian based distributions (e.g. Ubuntu), you may use pppoeconf package.

    This can be installed from the installation CDs or DVD.

    $> dpkg -l ppp* | grep ^ii
    ii ppp 2.4.4rel-4 Point-to-Point Protocol (PPP) daemon
    ii pppconfig 2.3.15 A text menu based utility for configuring pp
    ii pppoe 3.8-1.1 PPP over Ethernet driver
    ii pppoeconf 1.12 configures PPPoE/ADSL connections
    ii pppstatus 0.4.2-8 console-based PPP status monitor

  3. Detection of router/Modem

    Once the package installed, use the pppoeconf command as root to do the setup. This script will automatically detect the Network interface which is connected to the router/modem and will ask you the username, password and name servers. When it asks MTU, leave it as 1452 (for pppoe connections, max can be 1492, IIRC).

    After the setup, you give the command:

    #> pon dsl-provider
    to start the connection, and
    #> poff dsl-provider
    to stop the connection.

Note: You can also install the pppstatus package. It shows you the stats for your ppp connection (data speed, connection time, etc.) in a terminal.

Further Readings
  1. Check The Internet Usage on Netgear Router By Traffic Meter

  2. Cannot Access Internet After Installing New Wireless Router

  3. How to View Computers Connected to Netgear Wireless Network

  4. How to Configure Belkin Router With DSL Broadband Connection

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1 Supported Tata Mobile Broadband USB Modem in Linux
2Fix DNS Issues in Tata Photon Plus USB Modem
3 Steps to add Open DNS in Ubuntu Linux
Generations and distributions of Linux distros
PPOE configuration in Ubuntu Linux
How to Setup DSL Connection On Fedora Linux

Resolve Getting 169.254.X.X (APIPA) Windows Automatic Private IP Address

When a Windows computer failed to get valid IP address from DHCP server, OS will automatically assign a Windows generated Automatic Private IP address called APIPA to it. This automatic Private IP address is in the range to In a nutshell we can say any IP address in the range (169.254.X.X) is APIPA and it shows your computer is not connected to any network. Since APIPA (169.254.X.X) is a private IP address, your computer will not communicate to any other computers connected in the network(connected to a DHCP server). If you want your computer communicate to other computers in the network, you must change 169.254.X.X IP address by fixing the issues which prevent your computer from getting a valid IP address from DHCP server. This tutorial explains major reasons to get APIPA and how to resolve it.

APIPA = Automatic Private IP Addressing

All Windows versions like Windows 8, Windows 7, Vista, XP etc support APIPA except Windows NT. Follow the instructions below to fix 169.254.x.x addressing issues.

How to Resolve 169.254.X.X IP Address

  1. Release & Renew IP address

    When you notice APIPA on your computer, fist try to release and renew the ip address from command prompt. It will prompt your computer to contact DHCP server and renew current IP address. Commands to release and renew IP address on Windows versions from XP are:

    • ipconfig/release

    • ipconfig/renew

  2. Restart your computer

  3. Assign Static IP Address

    If your laptop does not change 169.254.x.x addressing, assign static IP to it according to the network address of DHCP server. For example if the address of DHCP server is, you can assign a static IP address in between to You must make sure don't assign a number which is used by other devices connected to the DHCP server.

  4. Ping the default gateway. If you are getting replies, try to go online and if you don't, follow the instructions

    • Check firewall settings & turn off all firewalls including windows firewall

    • Check the configuration of all Internet security software products.

  5. Power cycle the network

    To power cycle your network, follow the instructions provided in the link below.
    How to Power Cycle a Network

  6. If still having APIPA, use Following DOS prompt Commands

    • ipconfig /flushdns

    • netsh int ip reset c:\tcp.txt

    • netsh winsock reset

Fix Automatic Private IP Addressing Issues On Wireless Laptops

If you get APIPA On wireless PC or laptop, first step is to check whether the WiFi adapter or the Access Point is the source of the issue. If other devices on the WiFi network are working fine, you can ignore the steps on Router/AP. In my experience, most of the time getting APIPA is because of the faulty wireless adapter or corrupted WiFi utility installed. In thaa case, the below steps will fix the issue.

  1. Unplug and replug Wireless adapter (USB Adapters only)

  2. Update Wireless adapter driver

  3. Uninstall and reinstall wireless adapter driver

  4. Use Windows Wireless utility to manage wireless connection

  5. Delete the preferred networks and connect again to the current wireless network. If you are not sure how to do it, visit the link below. This link explains steps to do it on Windows 8, Windows 7 and XP computers.
    How to Delete Preferred Networks

  6. Faulty WiFi Monitoring Utility

    If your wireless computer is getting APIPA due to corrupted third party WiFi monitoring utility installed comes with adapter  on your computer, you may follow the instructions provided on the link below.

    • APIPA On Windows 8 and 7

      To fix APIPA on Windows 8, Vista and Windows 7 computers, follow the instructions provided in the link below. Here you will learn how to start WLAN AutoConfig instead of third party utilities like Linksys Wireless Monitor or Dell WiFi utility.
      Start WLAN AutoConfig Service

    • APIPA on Windows XP

      If you are running Windows XP, you should follow the instructions below to override corrupted Belkin Wireless Network Monitor Utility or D-Link wireless utility.
      How to Start WZC

Some Facts about APIPA

  1. It can be useful when you do not have a DHCP server.

  2. Even though your computer is assigned an APIPA, it will try to discover DHCP server in every five minutes.

  3. Subnet mask of APIPA is (Class B network).

  4. Computer having APIPA cannot communicate with devices in other subnets.

  5. Two computers having APIPA can communicate each other.
    How to Communicate Two Computers Having APIPA

Recommended Readings
  1. DOS Command to Start DORA

  2. What is DHCP Server & Its Working

  3. How to Fix IP Address Conflict In a Network

  4. Network Didn't Assign Valid IP Address in a Given Time. You May Not have Connectivity to Network

Technology Portal

Simple Guide For Router To Router Cascading

When you extend your current network, you may need to add more routers to the existing network. Without knowing how to perform router cascading, you will fail to add extra router to the network successfully. In this tutorial you will learn how to connect extra routers to the current network by cascading routers without having any network issues. There are two ways to cascade a router to another router. Before configuring the second router for router cascade, make sure that it is not connected to the main router (where the broadband modem is connected).

Different Methods to Cascade Two Routers
  1. LAN to LAN Router Cascade

    Connecting one of the Ethernet ports (LAN ports) of the second Router to one of the Ethernet ports (LAN ports) of the main router. In this method, the devices connected to the second router and the devices connected to the first router are in same network and can communicate each other directly.

  2. WAN to LAN Router Cascade

    Connecting the Internet port (WAN port) of the second Router to one of the Ethernet ports (LAN ports) of the main router. In this method, we are creating two different networks with different network addresses.
Let us check each methods to connect two routers to extend a network. Each methods have different effect in extending a network. Before going to configure settings on second router, you must have the IP address of the first router.

LAN to LAN Router Cascading Method

This method is used when you want to use same network address on devices connected to the second router. Here the second router is acting like a switch to extend your current network.
  1. Connect your computer to the LAN Port of the Router 2

  2. Login to Second Router

    Access the router’s web-based setup page{Second Router}. To learn how to access the web based setup page of a router, visit the link below.
    How to Find Login Address Of My Router

  3. Change the IP Address of Router 2

    When the router’s web-based setup page appears, look for Local IP Address and change it to “192.168.X.Y { Most of the times router IP address is 192.168.X.1 where X and Y starts from 0 to 255 }. We must ensure that Y is a number between 0 to 255 and is out of the DHCP range of router 1.

    Eg: Assign IP address 192.168.X.200 (Where X is the same value as in the router 1. Eg X value of router 1 with address is 1) to second router where the IP address of first router(main router connected to the modem) is 192.168.X.1

  4. Disable DHCP On Router 2

    When the web-based setup page opens, look for DHCP Server and click Disable. Do not forget to save settings. Click Advanced Routing and change Operating Mode to Router.(Depends on the router models and vendors this may change}.

  5. Connect Router 2 to Router 1

    Connect LAN Port of Router 1 to LAN Port of Router 2 using an Ethernet cable. Connect a standard Ethernet network cable to one of the numbered Ethernet ports on the main router, where the broadband modem is connected. Then, connect the other end of the Ethernet cable to the Ethernet port of the router that you have just configured.

If main router has IP address of with DHCP range 100, then the second router should have an IP address of Then only this kind of router cascade works.

Many users use this method to cascade a new wireless router with existing wired router to extend the router 1 to connect other wireless devices and still have the same network addresses assigned by first router. This method is very popular when a user need to cascade a wireless router with another existing router in the network. Do not confuse this method with step to cascade two wireless routers.

WAN to LAN Router Cascade(Method 2)

Before you connect a router to another router in WAN to LAN cascade Method, make sure that both routers have different IP addresses. If both routers have the same IP address, you need to change the IP address of the second router to prevent any conflict. Steps to configure second router in WAN to LAN cascading method are:
  1. Make sure Both Routers have Different Network Address

    If both routers have same network address (check the third octet and make sure both routers have different third octet number. Eg: for router 1 and for second router). If both routers have same third octet number, proceed to step 2.

  2. Change Third Octet of Router 2 IP Address

    Access the second router’s web-based setup page and look for Local IP Address and change it to “192.168.X.1 Where X is any number between 0 to 255 except the number in first router.[ie: If the IP address of the first router is the X of second router is any number between 0 to 255 other than 5]. Do not forget to save settings.

  3. Make sure DHCP server on second router is on

  4. Connect Second router to WAN port of First router

    Connect a standard Ethernet network cable to one of the numbered Ethernet ports on the main router, where the broadband modem is connected. Then connect the other end of the Ethernet cable to the Internet port of the router that you have just configured.

One of the most asked question from my readers is about possible issues with cascading routers from different vendors. There is no issues with cascading routers from different vendors. You won't face any issues with cascading a Linksys router with Belkin router or D-Link router because router cascading is vendor free.

Tutorials Related to Router Cascading

  1. Cascading three routers

    In a bigger network, you may need to cascade more than two routers. If you want to cascade third router to the second router, follow the instructions provided in the link below.
    How to Connect Third Router to Second Router

  2. Router cascading and Internet Speed

    Some users complains about reduced Internet speed after performing router cascade. The below link shows some instructions to troubleshoot the lose in Internet speed and some practical steps to improve the Internet speed after conducting two routers.
    How to speed up your Internet connection

New Topics in Networking