My ADD

20 October 2008

Wireless Network Types

Wireless Local Area Networks (WLANS)

WLANS allow users in local area, such as in a university or a library to form a network and gain wireless access to the internet. A temporary network can be formed by a small number of users without the need of access point; given that they do not need to access the resources.

Wireless Personal Area Networks (WPANS)

There are two current technologies for wireless personal network Bluetooth and Infra Red. These technologies will allow the connectivity of personal devices within an area of 30 feet. Infra Red requires a direct line and the range is less as compared to Bluetooth technology.

Wireless Metropolitan Area Networks (WMANS)

WMANS allow the connectivity of multiple networks in a metropolitan area such as building in a city. The network connectivity is the alternative of copper or fiber cabling.

Wireless Wide Area Networks (WWANS)

WWANS or Wireless Area Networks can be maintained over large areas such as in different cities or between different countries, via multiple satellite systems or antenna sites. The types of system are called 2G systems.

The following table shows the range those different types of wireless network covers.

Network Meter

Personal Area Network 0-10

Local Area Network 0-100

Wide Are Network 0-10000

Security in Wireless Networking

The following different types of security methods are available in the wireless networking.

Wired Equivalent Privacy (WEP)

Wired Equivalent Privacy is intended to stop the interference of radio frequency that is signaled by unauthorized users and this security measure is most suitable for the small networks. There is not key management protocol and each key is entered manually into the clients that’s why this is very time consuming administrative task. The WEP security method is based on the RC4 encryption algorithm. In the WEP all the client computers and Access points are configured with the same encryption and decryption keys.

Service Set Identifier (SSID)

Service Set Identifier (SSID) acts a simple password by allowing WLAN network to be split up into different networks and each having a unique identifier. These identifiers are configured in the multiple access points. To access any of any networks, a computer is configured in such a way that each is having a corresponding SSID identifier for that network. If the SSID match between the two computers or networks then access is granted to each other.

Media Access Control filtering (MAC Access Control)

A list of the MAC addresses of the client computers can be inputted into an Access point and only those computers are granted to give the access to the network. When a computer makes a request, its MAC address is compared to the list of the MAC addresses to the Access point and based on this access permission granted to deny.

This is a good security method but it is mainly involved in the small wireless networks because there is more manual work is involved of entering the MAC address into the Access point.

Bluetooth

Bluetooth is a simple type of the wireless networking that operates in the digital devices, like mobiles phones, personal computers, PDA, Laptops, digital camera, MP3 players and other Bluetooth enabled devices to form a small network. In the Bluetooth technology eight devices can be connected to each other at the same time. Bluetooth can also be found in the headsets, hands-free kits, wireless keyboards and mouse. Bluetooth technology was invented by Ericsson in 1994 and after four years in 1998 some major mobile phone companies such as Nokia, Ericsson, Intel and Toshiba formed a group to promote this technology.

Bluetooth technology falls in the category of personal area networking because it operates in the range of 30 to 300 feet. Bluetooth uses the radio waves technology, which is not very expensive and has low power consumption. Many different companies are intended to add the Bluetooth chip in their digital devices. Bluetooth technology is getting very popularity because of its low cost and portability.

The Future of Wireless Networking

WLANS wireless networking type is very popular in home networking and more than 20 percent homes with broadband internet are using WLANS and this number is increasing. In a general estimate worldwide hotspots have now reached more than 30,000 and will grow about 210,000 in the next few years. Most large hotels already offer Wi-Fi and the business travelers are willing to pay wireless access. 802.11 is the next Wi-Fi speed standard is set to offer bandwidth around 108Mbps and is still under development. With the speed of 70 Mbps and a range up to 30 miles, the 80216 standard, known as WiMAX is sure to get boost.

Some Tips & Tricks

• When purchasing a wireless NIC card try to get one that is having external antenna. When you are out and using Wi-Fi enabled laptop, disable Microsoft file and sharing, which enables other computers in a network to access data and resources on your computer. In this way, your computer or laptop will be saved from hackers.

• If you are concerned about the interference from the other wireless access point set the AP and wireless computers to use a non-overlapping channel.

• Change the configuration interface password of the access point before you enable it.

• Only buy an access point that is having upgradeable capabilities. By this way you can take the advantage of security enhancements.

• Keep the access point up to date.

19 October 2008

Configuring the Router

You will be able to learn the basic commands for configuring a router.
sh running-config - details the running configuration file (RAM)
sh startup-config - displays the configuration stored in NVRAM
setup - Will start the the automatic setup; the same as when you first boot the router
config t - use to execute configuration commands from the terminal
config mem - executes configuration commands stored in NVRAM; copies startup-config to running-config
config net - used to retrieve configuration info from a TFTP server
copy running-config startup-config - copies saved config in running config (RAM) to NVRAM or "write memory" for IOS under ver.11
copy startup-config running-config - copies from non-volatile (NVRAM) to current running config (RAM)
boot system flash - tells router which IOS file in flash to boot from
boot system tftp - tells router which IOS file on the tftp server to boot from
boot system rom - tell router to boot from ROM at next boot
copy flash tftp - Copies flash to tftp server
copy tftp flash - Restores flash from tftp server
copy run tftp - Copies the current running-config to tftp server
copy tftp run - Restores the running-config from tftp server

General Commands for Router

Here is a list of the general commands. These are the basic level commands and most commonly used
no shutdown - (enables the interface)
reload - restarts the router
sh ver - Cisco IOS version, uptime of router, how the router started, where system was loaded from, the interfaces the POST found, and the configuration register
sh clock - shows date and time on router
sh history - shows the history of your commands
sh debug - shows all debugging that is currently enabled
no debug all - turns off all debugging
sh users - shows users connected to router
sh protocols - shows which protocols are configured
banner motd # Your customized message here # - Set/change banner
hostname - use to configure the hostname of the router
clear counters - clear interface counters

Privileged Mode commands of a router

Learn how to work in the privileged mode of a router.

enable - get to privileged mode

disable - get to user mode

enable password - sets privileged mode password

enable secret - sets encrypted privileged mode password

Setting Passwords on router

Here you will be able to learn how to set the password on a router.

enable secret - set encrypted password for privileged access

enable password - set password for privileged access (used when there is no enable secret and when using older software)

Setting the password for console access:

(config)#line console 0

(config-line)#login

(config-line)#password

Set password for virtual terminal (telnet) access (password must be set to access router through telnet):

(config)#line vty 0 4

(config-line)#login

(config-line)#password
Set password for auxiliary (modem) access:

(config)#line aux 0

(config-line)#login

(config-line)#password

Router Processes & Statistics

By these command you can see the statistics and different processes of the router.

sh processes - shows active processes running on router
sh process cpu - shows cpu statistics
sh mem - shows memory statistics
sh flash - describes the flash memory and displays the size of files and the amount of free flash memory
sh buffers - displays statistics for router buffer pools; shows the size of the Small, Middle, Big, Very Big, Large and Huge Buffers
sh stacks - shows reason for last reboot, monitors the stack use of processes and interrupts routines

Frame-Relay Configuration

One of the methods for the WAN connectivity is the Frame Relay. Find here some basic commands for the WAN connectivity through Frame Relay.

encapsulation frame-relay ietf - use IETF when setting up a frame-relay network between a Ciscorouter and a non-Cisco router

frame-relay lmi-type ansi - LMI types are Cisco, ANSI, Q933A; Cisco is the default; LMI type is auto-sensed in IOS v11.2 and up

frame-relay map ip 3.3.3.3 100 broadcast - if inverse ARP won't work, map Other IP to Your DLCI # (local)

keep alive 10 - use to set keep alive

sh int ser 0 - use to show DLCI, LMI, and encapsulation info

sh frame-relay pvc - shows the configured DLCI's; shows PVC traffic stats

sh frame-relay map - shows route mapssh frame-relay lmi - shows LMI info

Cisco Certifications

General Certifications

  • CCNA

  • CCNP

  • CCIE

  • CCDP

  • CCDA

  • CCSP

  • CCIP

Wireless LAN Certifications

  • Cisco Advanced Wireless LAN Design Specialist

  • Cisco Advanced Wireless LAN Field Specialist

  • Cisco Advanced Wireless LAN Sales Specialist

VPN AND SECURITY CERTIFICATIONS

  • Cisco Firewall Specialist

  • Cisco IOS Security Specialist

  • Cisco IPS Specialist

  • Cisco Information Security Specialist

  • Cisco Security Sales Specialist

  • Cisco Network Admission Control Specialist

  • Cisco Security Solutions and Design Specialist

  • Cisco VPN Specialist

IP Communications Certifications

  • Cisco Advanced IP Communications Sales Specialist

  • Cisco IP Communications Express Specialist

  • Cisco IP Communications Express Sales Specialist

  • Cisco IP Contact Center Express Specialist

  • Cisco IP Telephony Design Specialist

  • Cisco Rich Media Communications Specialist

  • Cisco Unity Design Specialist

  • Cisco Unity Support Specialist

Data Center Certifications

  • Cisco Data Center Networking Infrastructure Design Specialist

  • Cisco Data Center Networking Infrastructure Support Specialist

  • Cisco Data Center Networking Sales Specialist

  • Data Center Storage Networking

  • Cisco Data Center Storage Networking Design Specialist

  • Cisco Data Center Storage Networking Support Specialist

  • Cisco Data Center Storage Networking Sales Specialist

Advanced Routing and Switching

  • Cisco Routing and Switching Field Specialist

  • Cisco Routing and Switching Sales Specialist

  • Cisco Routing and Switching Solutions Specialist

DHCP Tips

How DHCP Assigns Network Addresses to Your Computers
By John Enck, Windows NT Magazine October 1995.

How to Add Novell SLP DHCP Options to the DHCP Service
Microsoft Knowledge Base Article: 285019 - This article describes how to add Novell Service Location Protocol (SLP) DHCP options to the DHCP service.

HOW TO: Appoint an Administrator for DHCP Server Services in Windows 2000
Microsoft Knowledge Base Article: 303540 - This step-by-step article describes how to add users to the Dynamic Host Configuration Protocol (DHCP) Administrators group.

How to Configure Dynamic Host Configuration Protocol Servers with Split Scopes
Microsoft Knowledge Base Article: 280473 - This article describes how to configure Dynamic Host Configuration Protocol (DHCP) servers with split scopes.

How to Disable NetBIOS Over TCP/IP By Using DHCP Server Options
Microsoft Knowledge Base Article: 313314 - The Windows 2000 DHCP server provides a Vendor Class option you can use to disable the NetBIOS over TCP/IP for DHCP client. This article describes how to do this.

HOW TO: Install and Configure a Windows 2000 DHCP Server in an Active Directory Domain
Microsoft Knowledge Base Article: 300429 - This step-by-step article describes how to build and configure a new Windows 2000 DHCP Server in a Windows 2000 Active Directory domain. The Windows 2000 DHCP service provides clients with IP addresses, and information such as the location of their default gateway, DNS servers, and WINS servers.

HOW TO: Install and Configure a DHCP Server in a Workgroup in Windows 2000
Microsoft Knowledge Base Article: 301187 - This step-by-step guide describes how to configure a new Windows 2000-based Dynamic Host Configuration Protocol (DHCP) server on a standalone server to provide centralized management of IP addresses and other TCP/IP configuration settings for the client computers on a network.

How to Install Network Services Such as WINS and DNS in Windows 2000
Microsoft Knowledge Base Article: 261321 - The location for installing Windows Internet Name Service (WINS), Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), and other network services has changed in Windows 2000.

How to Move a DHCP Database to Another Windows NT Server
Microsoft Knowledge Base Article: 130642 Windows NT provides an administration utility called Dynamic Host Configuration Protocol (DHCP) Manager (Dhcpadmn.exe) that allows you to manage DHCP servers. However, Dhcpadmn.exe does not allow you to move a database from a server to another.
How to Remove and Reinstall DHCP and Keep the DHCP Config
Microsoft Knowledge Base Article: 169229. It is sometimes necessary to remove and then reinstall the DHCP Server service. This article explains how to perform this procedure and maintain your DHCP server settings.

How to Restore a Corrupted DHCP Database File
Microsoft Knowledge Base Article: 173396 This article discusses methods that may be used to recover a corrupted Dynamic Host Configuration Protocol (DHCP) database.

How to Upgrade a WINS or DHCP Database to Windows 2000
Microsoft Knowledge Base Article: 215416 Describes how to upgrade a DHCP or WINS database from a Microsoft Windows NT 3.51 server to a Windows 2000 server.

How to Use DHCP to Provide RAS Clients with DHCP Options
Microsoft Knowledge Base Article: 232703 - You can now use the DHCP Relay agent with RAS to provide DHCP scope options to RAS clients. The RAS client continues to receive an IP address from the RAS server, but may use DHCPInform packets to obtain WINS addresses, DNS addresses, domain.

How to Use Jetpack.exe to Compact a WINS or DHCP Database
Microsoft Knowledge Base Article: 145881 - Microsoft Windows NT Server includes a utility, Jetpack.exe, that can be used to compact a Windows Internet Name Service (WINS) or Dynamic Host Configuration Protocol (DHCP) database. Microsoft recommends that you compact the WINS database whenever it approaches 30 MB.

Increasing the Number of IP Addresses on a Subnet
Microsoft Knowledge Base Article: 255999 - This article describes methods you can use to change the number of IP hosts on any given subnet.

Installing DHCP and DDNS on a Domain Controller
Microsoft Knowledge Base Article: 255134 - Installing Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) on the same computer may allow name "hijacking." Evaluate the information in this article to determine whether it applies to your environment.

Issues in Network Connectivity.

If a computer is unable to connect to a network or see other computers in a network it may be necessary to troubleshoot the network. Due to the following reasons you network may not work.

1. Network card not connected properly

2. Bad NIC card drive's settings

3. Firewall preventing computers from seeing each other.

4. Connection related issues.

5. Bad network hardware.

07 October 2008

Wireless Networking Security Tips

The following tips are very helpful in securing your wireless computer network.

* Change the Default SSID

* Change the Default Administrator’s password

* Disable SSID broadcast.

* Enable Mac Address Filtering

* Assign Static IP address to the Network devices and computers.

* Turn on and configure the firewall on every computer in your network.

* Enable IPSec, SSL, Encryption, WPA and WPE according to your security requirements.

Network Tips|Troubleshooting

PING, IPCONFIG, Hostname, ARP, Telnet, NSLOOKUP, Tracert and many others. Pinging a network computer is the first troubleshooting step as it checks the connectivity with the destination computer. Additionally, you can use the other troubleshooting tools such as Ethereal, IP Sniffer, LanGuard, Packeteer and many others. These tools help to diagnose the cause of the problem and troubleshoot them.

Network Tips:Performance

To get the optimized performance from your computer network, you need to perform the following actions on every computer of your network.

o Use System Tools

o Delete Unnecessary Files

o Update Device Drivers

o Update BIOS

o Uninstall Unused Programs

o Update Operating System

Make Money Online

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Direct Sales
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Web Hosting
Web hosting is another great way of earning money on Internet. You need a reseller or affiliate account with a good web hosting company and you can sell the hosting space directly to the customers through your website.

Selling E-Books
Selling E-books at eBay.com is also a great way of generating income on net.

Content Writing
If you have writing skills then you can also generate income by writing content for different websites. You can get the content writer jobs at the elan's.com, through forums like forums.digitalpoint.com and through the organic traffic from the search engines.

Graphic Designer/Web Designer
If you are good at graphic and web designing then there is a great opportunity for you. Make your business website with an excellent portfolio and promote your website through the search engines,PPC, forums, email marketing and other promotion methods. On the web, there is a great scope for the web designers, graphic designers, web developers and webmasters.

Networking Tips|Connectivity

Computer networking sometimes considered to be complex and seems to hard to troubleshoot. The connectivity problems occur in the computer network due to the devices conflicts, outdated LAN card’s driver, faulty hardware, faulty cable or connectors and misconfiguration. To troubleshoot the connectivity related issues, you need to perform the following tasks.

* Check the LEDs of your LAN card.

* Update the driver of your LAN card.

* Scan your computer for the viruses and spy ware.

* Check the UTP/STP cable, the both end of the cable should be properly inserted

i.e. one end in the LAN card and one end in the hub/switch or router.

* Check the configurations of the LAN card.

* PING the destination computer and check the status.

* If your problem is still not resolved, replace the LAN card and reconfigure it.

Networking Tips|Security

A compute network is susceptible to the internet and external security related threats, which includes viruses, spyware, adware, Trojan horses, rootkits, web worms, intruders and hackers. To keep your network secure

Firewall: Install and configure a software/hardware firewall on your gateway and all other computers in your network. Firewall is used monitor the inbound and outbound traffic and block the unauthorized access and hackers’ attacks.

Antivirus: Install antivirus software such as Norton Antivirus, Trend Micro Office Scan, Panda Antivirus or McAfee and regularly scan your computer with an antivirus program.

Anti spyware: Install and configure an up-to-dated anti spyware software in your network.

Updated Operating System: Update your Windows based operating systems with the latest service packs, hot fixes and security patches.

Browser Security: Raise the level of security of your web browsers.

Private Network Tips

* Never use 192.168.0.0/24
* Never use 192.168.1.0/24
* Never use 10.0.0.0/24
* Never use 192.168.0.0/16
* Never use 10.0.0.0/8
* Heck, don't use ANYTHING in 192.168.0.0/16

Why? They are in use everywhere. At work, we created our private network many moons ago, and used 192.168.0.0/24 as the data network, and 192.168.1.0/24 as the voice network. And we have been regretting it ever since. This becomes a problem when a user tries to VPN in from his/her Linksys/Netgear/whatever network, which is invariably numbered 192.168.0.0/24 or 192.168.1.0/24. Hello network overlap!

Instead, pick a random range in the RFC1918 space. There are 256 possible /24s in 192.168.0.0/16. 65,536 /24s in 10.0.0.0/8. Heck, most people overlook 172.16.0.0/12, that's 4096 /24s right there. The following private networks have been randomly generated, just for you:

* 10.135.147.0/24
* 10.175.98.0/24
* 10.112.200.0/24
* 172.24.98.0/24
* 10.208.129.0/24

Reload to get more random private networks. A web page to specify other IP ranges/netmasks is coming soon. In the mean time, if you know PHP and want to see the source to this page, it is available

06 October 2008

Networking Computer Tips

Many people who take their notebook from home to the office may run into a problem of having to use a dynamic IP address at home and a static at the office. There is a way to have both settings in your configuration so you do not need to change them each time you change locations.

Go to your network connection properties by right clicking My Network Places and selecting Properties. Then right click your Local Area Connection icon and select Properties again. Select Internet Protocol (TCP/IP) and click on Properties. You will see a window similar to the following.

Click on the Alternate Configuration tab. Note that if you do not have Obtain an IP address automatically selected you will not see this tab

Enter your static IP information in the boxes and click OK.

One side effect of using this type of configuration is that it will take a little longer for Windows to completely load since it will first look for an IP address from a DHCP server before using the alternate configuration.

Free Way to Create Dynamic DNS

Dynamic DNS (DDNS)? This is a system that enables you to have dynamic IP address points to fixed domain name, so you don’t have to worry about domain name issue when the IP is changed as the domain name will point to new IP always.

If you have home network and connects to Internet by using DSL/Cable broadband connection with dynamic public IP, then you can make use of this DDNS to host web server, email server and other server by just using that dynamic public IP. Or if you have several web servers that tie to different public IP, then you can point the domain name to either one of the server IP and make system maintenance on other servers.

Interested to get one DDNS to use at home? Ok..I will show you how to register a free DDNS on www.DynDNS.com. Below are the free DDNS services provided by this website:

- Get five (5) hostnames in 88 available domains for free.
- Create wildcard CNAME *.yourhost.dyndns.org for yourhost.dyndns.org.
- Forward web requests or mark host offline for maintenance or downtime.
- Configure MX records for flexible mail routing.
- Update host using ddns update clients for a wide variety of platforms.
- Modify DNS TTL values for fast propagation or reliable static IP caching.
- Deliver your DNS records to 5 DNS servers in 5 tier-1 datacenters around the globe.

First you need to create an account on this DDNS website, then proceed to this DDNS link and click Get Started button. After that key in your username and password to proceed.

DDNS

Ok..Once you reach the following DDNS page, you can proceed to create your DDNS record. As an example, the hostname I choose is picohat and my dynamic DNS name is homeip.net. I also enable Wildcard and my Service Type is Host with IP address. Finally I key in my DSL broadband IP (60.54.61.117) as IP Address. I don’t enable Mail Routing because I don’t have any mail server in my home network. Click Create Host at last.

Note: You can always click that ? symbol in order to learn more on the DDNS settings, such as what is WebHop Redirect, Offline Hostname, etc.

Create Dynamic DNS

After that open the command prompt (cmd.exe), and try to resolve and ping the new domain name. For my case, I able to resolve the picohat.homeip.net to 60.54.61.117 and also can ping picohat.homeip.net. So it’s working!!!

Test Dynamic DNS

Backing Up Your ISP Settings

If you want to save your ISP settings (name, phone, login id etc.) for future installations:

1. Start Regedit

2. Go to HKEY_CURRENT_USER \ RemoteAccess

3. Select Registry / Export Registry

4. Make sure Selected branch is checked

5. For the name, enter any name that will help you remember the purpose of the .reg file

6. Now if you need to restore your ISP settings after a new installation of Windows, you just need to import this file